DEV: Convert min_trust_to_create_topic to groups (#24740)

This change converts the min_trust_to_create_topic site setting to
create_topic_allowed_groups.

See: https://meta.discourse.org/t/283408

- Hides the old setting
- Adds the new site setting
- Add a deprecation warning
- Updates to use the new setting
- Adds a migration to fill in the new setting if the old setting was
changed
- Adds an entry to the site_setting.keywords section
- Updates tests to account for the new change
- After a couple of months, we will remove the min_trust_to_create_topicsetting entirely.

Internal ref: /t/117248

spec/integration/watched_words_spec.rb

@@ -263,8 +263,9 @@ RSpec.describe WatchedWord do
     it "is compatible with flag_sockpuppets" do
       SiteSetting.flag_sockpuppets = true
       ip_address = "182.189.119.174"
-      user1 = Fabricate(:user, ip_address: ip_address, created_at: 2.days.ago)
-      user2 = Fabricate(:user, ip_address: ip_address)
+      user1 =
+        Fabricate(:user, ip_address: ip_address, created_at: 2.days.ago, refresh_auto_groups: true)
+      user2 = Fabricate(:user, ip_address: ip_address, refresh_auto_groups: true)
       first = create_post(user: user1, created_at: 2.days.ago)
       sockpuppet_post =
         create_post(