Delete command and bot message after cleaning messages

After purging messages, I believe the bot should delete both the command and the answer after there is enough time to read it. Since this doesn't happen, the only way to remove the clutter is by manually deleting, which is annoying >:/

Start by locating the command that purges messages and the handling of the bot's response. Confirm the intended delay that allows the response to be read, then trace how both messages can be removed. Done means the command and bot response are automatically deleted after the agreed delay, with behavior covered by the relevant tests if available.

Written by the indexing model from the issue text.