Replace vertical slider control

The current vertical slider implementation has a bug where the accessibility actions (increase volume, decrease volume, named "increment" and "decrement") do not work.

The current implementation is a control that wraps a horizontal slider and then rotates it 90° using a transform. This wrapping appears to be what causes the accessibility actions to not work. Worse, they cannot be removed because they are generated by the system.

Implementing our own vertical slider control from scratch and then adding these two accessibility options ourselves should fix the problem.

Relates to #1874