tv / bench: automatically get broadcast resolution from camera

We shouldn't have to set the resolution manually since firstly, there's only 1 option on the UI, secondly this information can be retrieved from the camera associated with the broadcast.

Start by locating the tv/bench UI and the broadcast logic that handles the camera association and resolution. Check how the single resolution option is currently supplied and whether the camera exposes the needed value. Done means the UI obtains the broadcast resolution from its associated camera without manual configuration.

Written by the indexing model from the issue text.