Allow the ability to hide/lock client permissions via Strategy

[andrewheberle]

In a corporate environment, allowing the remote user to control the permissions of the session is a problem and should be controllable via a Strategy.

Ideally this part of the UI would be completely hidden if all permissions were locked in the Strategy.

I had originally added this as a discussion item in the rustdesk/rustdesk repo but this is probably a more appropriate location.