Implement Media Sink Wants in Voice

[viztea]

Adds a new voice gateway command (op code 15) that controls whether the voice server sends voice packets to the bot.

Still a bit unsure on the API since Kord voice allows setting the deafen value when joining and the streams implementation to use.

[lukellmann]

i'm curious, are there any resources to read up on this feature? it isn't documented in the discord developer portal yet

[viztea]

i'm curious, are there any resources to read up on this feature? it isn't documented in the discord developer portal yet

It isn't documented, just like voice receive (which is supported by kord voice), this was discovered through reverse engineering the official Discord Client.

[lost-illusi0n]

Functionality-wise LGTM.