refactor: remove user bot methods (#2559)

* [WIP] Remove user bots

* more backend userbot removal

* Add mfaEnabled back

* revert client presences store removal

* partially revert getAuth changes

* remove more no longer used children of ClientUserGuildSettings

* fix a bug with this pr and TextBasedChannel.applyToClass

* remove a syncGuilds reference

* more user bot data handling

* various guildSync cleanup

* bots can't call logout

Had the user/bot portions of the code mixed up. Though, does this need to be a promise anymore?

* make ClientManager#destroy() sync

It nolonger needs to be a promise, and nothing depended on it being a promise that I can tell.

* requested change

* Fix massive error

* no longer used as it's userbot only

src/stores/MessageStore.js

@@ -1,7 +1,6 @@
 const DataStore = require('./DataStore');
 const Collection = require('../util/Collection');
 const Message = require('../structures/Message');
-const { Error } = require('../errors');
 
 /**
  * Stores messages for text-based channels.
@@ -80,12 +79,6 @@ class MessageStore extends DataStore {
   }
 
   async _fetchId(messageID) {
-    if (!this.client.user.bot) {
-      const messages = await this._fetchMany({ limit: 1, around: messageID });
-      const msg = messages.get(messageID);
-      if (!msg) throw new Error('MESSAGE_MISSING');
-      return msg;
-    }
     const data = await this.client.api.channels[this.channel.id].messages[messageID].get();
     return this.add(data);
   }