Add better control for users of comments displayed on their videos:
* Do not forward comments from muted remote accounts/servers (muted by the current server or by the video owner)
* Do not list threads and hide replies (with their children) of accounts/servers muted by the video owner
* Hide from RSS comments of muted accounts/servers by video owners
Use case:
* Try to limit spam propagation in the federation
* Add ability for users to automatically hide comments on their videos from undesirable accounts/servers (the comment section belongs to videomakers, so they choose what's posted there)
