FEATURE: Rename 'Discourse SSO' to DiscourseConnect (#11978)

The 'Discourse SSO' protocol is being rebranded to DiscourseConnect. This should help to reduce confusion when 'SSO' is used in the generic sense.

This commit aims to:
- Rename `sso_` site settings. DiscourseConnect specific ones are prefixed `discourse_connect_`. Generic settings are prefixed `auth_`
- Add (server-side-only) backwards compatibility for the old setting names, with deprecation notices
- Copy `site_settings` database records to the new names
- Rename relevant translation keys
- Update relevant translations

This commit does **not** aim to:
- Rename any Ruby classes or methods. This might be done in a future commit
- Change any URLs. This would break existing integrations
- Make any changes to the protocol. This would break existing integrations
- Change any functionality. Further normalization across DiscourseConnect and other auth methods will be done separately

The risks are:
- There is no backwards compatibility for site settings on the client-side. Accessing auth-related site settings in Javascript is fairly rare, and an error on the client side would not be security-critical.
- If a plugin is monkey-patching parts of the auth process, changes to locale keys could cause broken error messages. This should also be unlikely. The old site setting names remain functional, so security-related overrides will remain working.

A follow-up commit will be made with a post-deploy migration to delete the old `site_settings` rows.

spec/models/discourse_single_sign_on_spec.rb

@@ -4,12 +4,12 @@ require "rails_helper"
 
 describe DiscourseSingleSignOn do
   before do
-    @sso_url = "http://example.com/discourse_sso"
-    @sso_secret = "shjkfdhsfkjh"
+    @discourse_connect_url = "http://example.com/discourse_sso"
+    @discourse_connect_secret = "shjkfdhsfkjh"
 
-    SiteSetting.sso_url = @sso_url
-    SiteSetting.enable_sso = true
-    SiteSetting.sso_secret = @sso_secret
+    SiteSetting.discourse_connect_url = @discourse_connect_url
+    SiteSetting.enable_discourse_connect = true
+    SiteSetting.discourse_connect_secret = @discourse_connect_secret
     Jobs.run_immediately!
   end
 
@@ -114,7 +114,7 @@ describe DiscourseSingleSignOn do
   end
 
   it "unstaged users" do
-    SiteSetting.sso_overrides_name = true
+    SiteSetting.auth_overrides_name = true
 
     email = "staged@user.com"
     Fabricate(:user, staged: true, email: email)
@@ -195,7 +195,7 @@ describe DiscourseSingleSignOn do
     sso.groups = "#{group2.name.capitalize},group4,badname,trust_level_4"
     sso.lookup_or_create_user(ip_address)
 
-    SiteSetting.sso_overrides_groups = true
+    SiteSetting.discourse_connect_overrides_groups = true
 
     group1.reload
     expect(group1.usernames).to eq("")
@@ -260,7 +260,7 @@ describe DiscourseSingleSignOn do
   end
 
   it 'can override username properly when only the case changes' do
-    SiteSetting.sso_overrides_username = true
+    SiteSetting.auth_overrides_username = true
 
     sso = DiscourseSingleSignOn.new
     sso.username = "testuser"
@@ -280,8 +280,8 @@ describe DiscourseSingleSignOn do
     expect(user.username).to eq "TestUser"
   end
 
-  it 'behaves properly when sso_overrides_username is set but username is missing or blank' do
-    SiteSetting.sso_overrides_username = true
+  it 'behaves properly when auth_overrides_username is set but username is missing or blank' do
+    SiteSetting.auth_overrides_username = true
 
     sso = DiscourseSingleSignOn.new
     sso.username = "testuser"
@@ -310,9 +310,9 @@ describe DiscourseSingleSignOn do
     admin = Fabricate(:admin)
 
     SiteSetting.email_editable = false
-    SiteSetting.sso_overrides_name = true
-    SiteSetting.sso_overrides_email = true
-    SiteSetting.sso_overrides_username = true
+    SiteSetting.auth_overrides_name = true
+    SiteSetting.auth_overrides_email = true
+    SiteSetting.auth_overrides_username = true
 
     sso = DiscourseSingleSignOn.new
     sso.username = "bob%the$admin"
@@ -378,7 +378,7 @@ describe DiscourseSingleSignOn do
 
   it "generates a correct sso url" do
     url, payload = DiscourseSingleSignOn.generate_url.split("?")
-    expect(url).to eq @sso_url
+    expect(url).to eq @discourse_connect_url
 
     sso = DiscourseSingleSignOn.parse(payload)
     expect(sso.nonce).to_not be_nil
@@ -447,7 +447,7 @@ describe DiscourseSingleSignOn do
 
     it 'does not deactivate user if email provided is capitalized' do
       SiteSetting.email_editable = false
-      SiteSetting.sso_overrides_email = true
+      SiteSetting.auth_overrides_email = true
       sso.require_activation = true
 
       user = sso.lookup_or_create_user(ip_address)
@@ -465,7 +465,7 @@ describe DiscourseSingleSignOn do
     it 'deactivates accounts that have updated email address' do
 
       SiteSetting.email_editable = false
-      SiteSetting.sso_overrides_email = true
+      SiteSetting.auth_overrides_email = true
       sso.require_activation = true
 
       user = sso.lookup_or_create_user(ip_address)
@@ -567,7 +567,7 @@ describe DiscourseSingleSignOn do
 
       # yes override if site setting
       sso.bio = "new profile 2"
-      SiteSetting.sso_overrides_bio = true
+      SiteSetting.discourse_connect_overrides_bio = true
 
       user = sso.lookup_or_create_user(ip_address)
       expect(user.user_profile.bio_cooked).to match_html("<p>new profile 2</p")
@@ -575,7 +575,7 @@ describe DiscourseSingleSignOn do
 
   end
 
-  context 'when sso_overrides_avatar is not enabled' do
+  context 'when discourse_connect_overrides_avatar is not enabled' do
 
     it "correctly handles provided avatar_urls" do
       sso = DiscourseSingleSignOn.new
@@ -635,7 +635,7 @@ describe DiscourseSingleSignOn do
 
   end
 
-  context 'when sso_overrides_avatar is enabled' do
+  context 'when discourse_connect_overrides_avatar is enabled' do
     fab!(:sso_record) { Fabricate(:single_sign_on_record, external_avatar_url: "http://example.com/an_image.png") }
 
     let!(:sso) {
@@ -650,7 +650,7 @@ describe DiscourseSingleSignOn do
     let(:logo) { file_from_fixtures("logo.png") }
 
     before do
-      SiteSetting.sso_overrides_avatar = true
+      SiteSetting.discourse_connect_overrides_avatar = true
     end
 
     it "deal with no avatar url passed for an existing user with an avatar" do
@@ -683,7 +683,7 @@ describe DiscourseSingleSignOn do
     end
   end
 
-  context 'when sso_overrides_profile_background is not enabled' do
+  context 'when discourse_connect_overrides_profile_background is not enabled' do
 
     it "correctly handles provided profile_background_urls" do
       sso = DiscourseSingleSignOn.new
@@ -715,7 +715,7 @@ describe DiscourseSingleSignOn do
     end
   end
 
-  context 'when sso_overrides_profile_background is enabled' do
+  context 'when discourse_connect_overrides_profile_background is enabled' do
     fab!(:sso_record) { Fabricate(:single_sign_on_record, external_profile_background_url: "http://example.com/an_image.png") }
 
     let!(:sso) {
@@ -730,7 +730,7 @@ describe DiscourseSingleSignOn do
     let(:logo) { file_from_fixtures("logo.png") }
 
     before do
-      SiteSetting.sso_overrides_profile_background = true
+      SiteSetting.discourse_connect_overrides_profile_background = true
     end
 
     it "deal with no profile_background_url passed for an existing user with a profile_background" do
@@ -755,7 +755,7 @@ describe DiscourseSingleSignOn do
     end
   end
 
-  context 'when sso_overrides_card_background is not enabled' do
+  context 'when discourse_connect_overrides_card_background is not enabled' do
 
     it "correctly handles provided card_background_urls" do
       sso = DiscourseSingleSignOn.new
@@ -787,7 +787,7 @@ describe DiscourseSingleSignOn do
     end
   end
 
-  context 'when sso_overrides_card_background is enabled' do
+  context 'when discourse_connect_overrides_card_background is enabled' do
     fab!(:sso_record) { Fabricate(:single_sign_on_record, external_card_background_url: "http://example.com/an_image.png") }
 
     let!(:sso) {
@@ -802,7 +802,7 @@ describe DiscourseSingleSignOn do
     let(:logo) { file_from_fixtures("logo.png") }
 
     before do
-      SiteSetting.sso_overrides_card_background = true
+      SiteSetting.discourse_connect_overrides_card_background = true
     end
 
     it "deal with no card_background_url passed for an existing user with a card_background" do