Add DAVE protocol support

[Snazzah]

Summary

Implements the Discord Audio & Video End-to-End Encryption (DAVE) Protocol into the voice client and voice state.

This requires the python dependency davey, this is still new and is yet to be reviewed by others, but has proper typings and has multiple builds.

TODO

• Update documentation for DAVE
• Misc reviews

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)