Add voice channel status events and permission

[Puncher1]

Summary

This PR adds the events and permission for the voice channel status.

Note: The implementation of the endpoint to set the voice channel status is seperated into a second PR (#9603) because it cannot be merged due to the experiment lock, which this PR already can.

Related PR: discord/discord-api-docs#6398

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, ...)

[Puncher1]

I used the constructor instead of an _update method to assign the status because a channel update would overwrite self.status to None since the status is not in the payload of a channel update. In the client however, if you edit the channel the status gets reset which I assume is a UI bug (see this comment: discord/discord-api-docs#6398 (comment))

[Rapptz]

Looks mostly okay, however not a big fan on the event at the moment. We're kind of moving away from this style of event but it was too late to commit to it in v2 due to churn.