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/structures/GroupDMChannel.js

@@ -184,16 +184,12 @@ class GroupDMChannel extends Channel {
    * @param {Object} options Options for this method
    * @param {UserResolvable} options.user User to add to this Group DM
    * @param {string} [options.accessToken] Access token to use to add the user to this Group DM
-   * (only available under a bot account)
-   * @param {string} [options.nick] Permanent nickname to give the user (only available under a bot account)
+   * @param {string} [options.nick] Permanent nickname to give the user
    * @returns {Promise<GroupDMChannel>}
    */
   addUser({ user, accessToken, nick }) {
     const id = this.client.users.resolveID(user);
-    const data = this.client.user.bot ?
-      { nick, access_token: accessToken } :
-      { recipient: id };
-    return this.client.api.channels[this.id].recipients[id].put({ data })
+    return this.client.api.channels[this.id].recipients[id].put({ nick, access_token: accessToken })
       .then(() => this);
   }