Activities limitations

How about applying limitations and controls to the activities in voice chat? In particular the following:
- Admin permission to toggle each activity, so that you only allow certain activities in certain channels, eg a dedicated game for each channel, or removing activities you don't want played in that channel
- Automatic startup of a chosen activity upon at least one member joining the voice chat, as well as automatic joining of the activity upon others joining the chat whilst the activity is active.
- For the Youtube Watch Together activity, possibly set a default video url per channel and prevent the use of search, so that only the selected video plays on repeat. Useful for themed/rp/ambience channels, less fiddling about from the regular members or choosing a video that doesn't match with the server theme.