FEATURE: Count only approved flagged posts in user pages (#22799)

FEATURE: Only approved flags for post counters

* Why was this change necessary?
The counters for flagged posts in the user's profile and user index from
the admin view include flags that were rejected, ignored or pending
review. This introduces unnecessary noise. Also the flagged posts
counter in the user's profile includes custom flags which add further
noise to this signal.

* How does it address the problem?

* Modifying User#flags_received_count to return posts with only approved
  standard flags
* Refactoring User#number_of_flagged_posts to alias to
  User#flags_received_count
* Updating the flagged post staff counter hyperlink to navigate to a
  filtered view of that user's approved flagged posts to maintain
  consistency with the counter
* Adding system tests for the profile page to cover the flagged posts
  staff counter

app/models/user.rb

@@ -1202,13 +1202,6 @@ class User < ActiveRecord::Base
     user_warnings.count
   end
 
-  def flags_received_count
-    posts
-      .includes(:post_actions)
-      .where("post_actions.post_action_type_id" => PostActionType.flag_types_without_custom.values)
-      .count
-  end
-
   def private_topics_count
     topics_allowed.where(archetype: Archetype.private_message).count
   end
@@ -1539,8 +1532,14 @@ class User < ActiveRecord::Base
   end
 
   def number_of_flagged_posts
-    ReviewableFlaggedPost.where(target_created_by: self.id).count
+    posts
+      .with_deleted
+      .includes(:post_actions)
+      .where("post_actions.post_action_type_id" => PostActionType.flag_types_without_custom.values)
+      .where("post_actions.agreed_at IS NOT NULL")
+      .count
   end
+  alias_method :flags_received_count, :number_of_flagged_posts
 
   def number_of_rejected_posts
     ReviewableQueuedPost.rejected.where(target_created_by_id: self.id).count