feat: Add "deleted" property to multiple structures. (#2556)

* Add "deleted" property to "Message" structure

* Add "deleted" property to Multiple structures

Structures edited:
- Channel
- Emoji
- Guild
- Guild Member
- Role

* Update "deletable" getter

* Fix ESLint "no-trailing-spaces" errors

* Requested Change: Mark w/ bulkDelete

src/structures/Channel.js

@@ -23,6 +23,12 @@ class Channel extends Base {
      */
     this.type = type ? type.toLowerCase() : 'unknown';
 
+    /**
+     * Whether the channel has been deleted
+     * @type {boolean}
+     */
+    this.deleted = false;
+
     if (data) this._patch(data);
   }