FIX: Better tracking of topic visibility changes (#26709)

This commit introduces a few changes as a result of
customer issues with finding why a topic was relisted.
In one case, if a user edited the OP of a topic that was
unlisted and hidden because of too many flags, the topic
would get relisted by directly changing topic.visible,
instead of going via TopicStatusUpdater.

To improve tracking we:

* Introduce a visibility_reason_id to topic which functions
  in a similar way to hidden_reason_id on post, this column is
  set from the various places we change topic visibility
* Fix Post#unhide! which was directly modifying topic.visible,
  instead we use TopicStatusUpdater which sets visibility_reason_id
  and also makes a small action post
* Show the reason topic visibility changed when hovering the
  unlisted icon in topic status on topic titles

app/controllers/topics_controller.rb

@@ -497,6 +497,18 @@ class TopicsController < ApplicationController
         Topic.find_by(id: topic_id)
       end
 
+    status_opts = { until: params[:until].presence }
+
+    if status == "visible"
+      status_opts[:visibility_reason_id] = (
+        if enabled
+          Topic.visibility_reasons[:manually_relisted]
+        else
+          Topic.visibility_reasons[:manually_unlisted]
+        end
+      )
+    end
+
     case status
     when "closed"
       guardian.ensure_can_close_topic!(@topic)
@@ -510,9 +522,7 @@ class TopicsController < ApplicationController
       guardian.ensure_can_moderate!(@topic)
     end
 
-    params[:until] === "" ? params[:until] = nil : params[:until]
-
-    @topic.update_status(status, enabled, current_user, until: params[:until])
+    @topic.update_status(status, enabled, current_user, status_opts)
 
     render json:
              success_json.merge!(