[Logging] Message event logs for deletion don't distinguish "message sender" from "message deleter"

[lee0c]

It would be very helpful to have logs for message deletion that outline both

1. The user who sent the message
2. The user or bot who deleted the message

Currently, the message and it's author is logged, but there's no record of who deleted it.

This would help catch abuse of permissions that allow users to delete others' messages (I have this available in a small server in order to enable easier pinning).