[Feature request] add a way to approve requests

[Iguana9999phil]

Would like to see a option to be able to approve / deny requests when using the direct integration with sonarr/radarr. This would make mellow a great little bot and a great alternative for Ombi.

My idea (no idea how it works technically): When a user requests media and click the arrow, let the bot send an DM to a set admin discord users with the option to allow or deny it, (possibly also to let him choose from a set root paths) after approval send it to sonarr / Radarr.