Add accept and unaccept solution events

plugin.rb

@@ -53,6 +53,8 @@ after_initialize do
                           )
       end
 
+      DiscourseEvent.trigger(:accepted_solution, post)
+
       render json: success_json
     end
 
@@ -79,6 +81,8 @@ after_initialize do
 
       notification.destroy if notification
 
+      DiscourseEvent.trigger(:unaccepted_solution, post)
+
       render json: success_json
     end