DEV: Convert approve_unless_trust_level to groups (#24357)

This change converts the `approve_unless_trust_level` site setting to
`approve_unless_allowed_groups`.

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

- Adds the new site setting
- Adds a deprecation warning
- Updates core to use the new settings.
- Adds a migration to fill in the new setting of the old setting was
  changed
- Adds an entry to the site_setting.keywords section
- Updates many tests to account for the new change

After a couple of months we will remove the `approve_unless_trust_level`
setting entirely.

Internal ref: /t/115696

spec/system/composer/category_templates_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 describe "Composer Form Templates", type: :system do
-  fab!(:user)
+  fab!(:user) { Fabricate(:user, refresh_auto_groups: true) }
   fab!(:form_template_1) do
     Fabricate(
       :form_template,

spec/system/composer/review_media_unless_trust_level_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 describe "Composer using review_media", type: :system do
-  fab!(:user)
+  fab!(:user) { Fabricate(:user, refresh_auto_groups: true) }
   fab!(:topic) { Fabricate(:topic, category: Category.find(SiteSetting.uncategorized_category_id)) }
   fab!(:post) { Fabricate(:post, topic: topic) }
   let(:topic_page) { PageObjects::Pages::Topic.new }

spec/system/hashtag_autocomplete_spec.rb

@@ -100,6 +100,7 @@ describe "Using #hashtag autocompletion to search for and lookup categories and
   end
 
   it "cooks the hashtags for tag and category correctly serverside when the post is saved to the database" do
+    Group.refresh_automatic_groups!
     topic_page.visit_topic_and_open_composer(topic)
 
     expect(topic_page).to have_expanded_composer