Allow DMs the ability to rollback edits and deletes (Moderation/Harassment purposes)

Simply put, as a guy who runs a moderation team, I take the stance that I need proof or I will not act on it to keep my moderation as ethical as possible.

There's been some cases where people will mass ping or send vile/harassing messages, then delete or edit them later to remove evidence.

Realistically, the easiest thing to do would be to simply turn off the ability to delete/edit DMs to accomplish this.

I'd like to suggest to basically allow users to "roll back" a DM to the first edit of a post and undelete everything up to a certain time period (Say 3 days to 1 week) so we have proof of malicious acts.