Implement online sync of Collections between different Bitwarden servers

Now Bitwarden database is locked to only one server. But when on some project starts working more than one company (which use personal servers for private reasons), they needs to share some collection between several severs, and this is not possible now. So now the solution is only manual syncing of collections between servers via hands.

Will be good to have ability to share some collection for other server(s), to keep it always in sync on both servers.