Add `prune X` command to remove last X messages in the current channel

[Elanis]

In the process to stop using Dyno on "Not a name" server, we will need this command to be added in Not A Bot.

prune X command is used to remove last X messages in the current channel. It should remove the command message as well (but not counted in the X counter.

[Julien00859]

I would like a command that is prune <message-id> where message-id is a message identifier in the current server, e.g. 358924179954860033-860919802435469353 for https://discord.com/channels/323076998576603137/358924179954860033/860919802435469353. This command would delete all the messages starting at <message-id> included.

[Elanis]

This Issue can be closed thanks to #80