Define permissions for Managed VCs

[Ryeera]

In all managed VCs, there will be the following roles. The only mandatory role is the channel-owner which is set by default to be the creator of the managed VC.

Channel Owner

The owner has all permissions for this single channel, which allows them to set up all channel settings to their liking.
The owner can also assign members as channel-admins as well as channel-moderators which will grant the according permissions for this channel.
The owner is the only person who can grant and revoke channel-admin-permissions.
Both the owner and the channel-admins can grant and revoke channel-moderator-permissions.

Channel Admin

Channel Admins have all permissions in a managed VC except for appointing new channel-admins and changing the owner of the managed VC.
Both the owner and the channel-admins can grant and revoke channel-moderator-permissions.

Channel Moderator

Channel Moderators have moderation-permissions like Disconnect, Kick, Mute, Deafen etc.
They cannot moderate the Channel Admins nor the Channel Owner.

Refer to issue #11 for how configuration of these settings as well as the usage as the moderation-features is supposed to work.