DEV: Move core plugin TL -> group settings (#25355)

* DEV: Change poll_minimum_trust_level_to_create to group based setting

New setting is poll_create_allowed_groups

c.f. https://meta.discourse.org/t/changes-coming-to-settings-for-giving-access-to-features-from-trust-levels-to-groups/283408

* DEV: Move styleguide_admin_only to group based setting

Not exactly a TL -> group change, but still part of the
overall effort here:

https://meta.discourse.org/t/changes-coming-to-settings-for-giving-access-to-features-from-trust-levels-to-groups/283408

New setting is styleguide_allowed_groups

plugins/poll/spec/controllers/polls_controller_spec.rb

@@ -33,6 +33,8 @@ RSpec.describe ::DiscoursePoll::PollsController do
     )
   end
 
+  before { Group.refresh_automatic_groups! }
+
   describe "#vote" do
     it "works" do
       channel = "/polls/#{poll.topic_id}"