FEATURE: Add setting to show who marked as solved (#347)

This commit adds the site setting `SiteSetting.show_who_marked_solved` and also the following tooltip to answer posts.

lib/discourse_solved/topic_view_serializer_extension.rb

@@ -36,11 +36,14 @@ module DiscourseSolved::TopicViewSerializerExtension
       post_number: answer_post.post_number,
       username: answer_post_user.username,
       name: answer_post_user.name,
-      accepter_username: accepter.username,
-      accepter_name: accepter.name,
       excerpt:,
     }
 
+    if SiteSetting.show_who_marked_solved
+      accepted_answer[:accepter_name] = accepter.name
+      accepted_answer[:accepter_username] = accepter.username
+    end
+
     if !SiteSetting.enable_names || !SiteSetting.display_name_on_posts
       accepted_answer[:name] = nil
       accepted_answer[:accepter_name] = nil