Added new /revokeinvites slash command.

[hitblast]

This PR adds:

• A new slash command named /revokeinvites which can primarily be used to revoke / delete all the invites in the server. There is also a member option which you can use to delete invites created by a specific inviter.
• The message command equivalent of the upper change.

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Legend

[furtidev]

LGTM! 🚀

[hitblast]

Thanks for the merge!