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/rest/RESTManager.js

@@ -25,7 +25,7 @@ class RESTManager {
 
   getAuth() {
     const token = this.client.token || this.client.accessToken;
-    const prefixed = !!this.client.application || (this.client.user && this.client.user.bot);
+    const prefixed = !!this.client.application || this.client.user;
     if (token && prefixed) return `${this.tokenPrefix} ${token}`;
     else if (token) return token;
     throw new Error('TOKEN_MISSING');