Viewer improvement: Vertical screens

[cpvalente]

It would be good to have nicer designs for vertical screens, especially on public and backstage views Should also accomodate for lower resolutions. find a minimum expected resolution and ensure that everything looks ok perhaps 1280 x 720 would be good

Once this is completed, there should also be a button to rotate the screen 90 degrees

Should also look into avoiding content shifts when timers go negative