cleanup: remove unused members of classes (#3078)

* cleanup: Remove unused members of classes

* typings: Remove hit from Message

src/structures/Message.js

@@ -153,12 +153,6 @@ class Message extends Base {
       type: data.activity.type,
     } : null;
 
-    /**
-     * Whether this message is a hit in a search
-     * @type {?boolean}
-     */
-    this.hit = typeof data.hit === 'boolean' ? data.hit : null;
-
     /**
      * The previous versions of the message, sorted with the most recent first
      * @type {Message[]}