FEATURE: mandatory fields for group site setting (#26612)

Automatically add `moderators` and `admins` auto groups to specific site settings.

In the new group-based permissions systems, we just want to check the user’s groups since it more accurately reflects reality

Affected settings:
- tag_topic_allowed_groups
- create_tag_allowed_groups
- send_email_messages_allowed_groups
- personal_message_enabled_groups
- here_mention_allowed_groups
- approve_unless_allowed_groups
- approve_new_topics_unless_allowed_groups
- skip_review_media_groups
- email_in_allowed_groups
- create_topic_allowed_groups
- edit_wiki_post_allowed_groups
- edit_post_allowed_groups
- self_wiki_allowed_groups
- flag_post_allowed_groups
- post_links_allowed_groups
- embedded_media_post_allowed_groups
- profile_background_allowed_groups
- user_card_background_allowed_groups
- invite_allowed_groups
- ignore_allowed_groups
- user_api_key_allowed_groups

spec/requests/admin/site_settings_controller_spec.rb

@@ -259,7 +259,7 @@ RSpec.describe Admin::SiteSettingsController do
 
         expect(response.status).to eq(422)
         expect(SiteSetting.personal_message_enabled_groups).to eq(
-          Group::AUTO_GROUPS[:trust_level_4],
+          "1|2|#{Group::AUTO_GROUPS[:trust_level_4]}",
         )
       end