Add Auditlog reason to Bulk delete and add deletion of (other) messages to audit logs

[Andre601]

Since Bulk delete actions are also logged in the audit log now would it only be logical to allow setting an audit log reason for the action.
That way could moderation bots much easier tell the reason of why messages where deleted and moderators could give a reason as to why they deleted the messages through the bot.

In addition, would it also be beneficial to log bots deleting messages of other members.
The Audit logs right now do only log it, when a normal user (moderator) deletes the message of someone else but doesn't log it when a bot does this. This will make the audit logs unreliable as you can't tell for sure which bot deleted the message now.
And if we would add this, also make it possible to have a visible reason for it in the logs too. ❤️