FEATURE: Reason and deleted content support in the review queue (#30295)

Add flag reason filter and improve handling of deleted content in review queue

This commit enhances the review queue with several key improvements:

1. Adds a new "Reason" filter to allow filtering flags by their score type
2. Improves UI for deleted content by:
   - Adding visual indication for deleted posts (red background)
   - Properly handling deleted content visibility for staff (category mods can not see deleted content)
3. Refactors reviewable score type handling for better code organization
4. Adds  tests for trashed topics/posts visibility

This change will help moderators more efficiently manage the review queue by
being able to focus on specific types of flags and better identify deleted
content.

app/models/reviewable.rb

@@ -449,7 +449,8 @@ class Reviewable < ActiveRecord::Base
     additional_filters: {},
     preload: true,
     include_claimed_by_others: true,
-    flagged_by: nil
+    flagged_by: nil,
+    score_type: nil
   )
     order =
       case sort_order
@@ -489,6 +490,16 @@ class Reviewable < ActiveRecord::Base
       SQL
     end
 
+    if score_type
+      score_type = score_type.to_i
+      result = result.where(<<~SQL, score_type: score_type)
+      EXISTS(
+        SELECT 1 FROM reviewable_scores
+        WHERE reviewable_scores.reviewable_id = reviewables.id AND reviewable_scores.reviewable_score_type = :score_type
+      )
+      SQL
+    end
+
     if reviewed_by
       reviewed_by_id = User.find_by_username(reviewed_by)&.id
       return none if reviewed_by_id.nil?

app/models/reviewable_score.rb

@@ -14,6 +14,12 @@ class ReviewableScore < ActiveRecord::Base
     @types ||= PostActionType.flag_types.merge(PostActionType.score_types)
   end
 
+  def self.type_title(type)
+    I18n.t("post_action_types.#{type}.title", default: nil) ||
+      I18n.t("reviewable_score_types.#{type}.title", default: nil) ||
+      PostActionType.names[types[type]]
+  end
+
   # When extending post action flags, we need to call this method in order to
   # get the latests flags.
   def self.reload_types