feat: Add UI support for PTZ presets (#1920)

- Closes #1889

Whilst a simple change theoretically, the card has such a collection of
surfaces that can overlap other surfaces, it's challenging to get this
to work right! There's a real chance this will have broken something
z-index related (e.g. X overlaps Y when it should not), or (for related
reasons) broken curver corners on the card.

src/scss/media-grid.scss

@@ -43,10 +43,6 @@
         var(--advanced-camera-card-grid-column-size)
     )
   );
-
-  // When at item is selected, it may be enlarged -- it should render "in-front"
-  // of the other cameras that will then "move out of the way".
-  z-index: 2;
 }
 
 slot {