Feature Request: Arrows on 2D Layer Scroll Bar (i.e. +1, -1 buttons)

[b-morgan]

Could you add the "arrows" to the ends of the 2D Layer Scroll Bar (or all scroll bars) that do +1, and -1?

If that is not possible, can you add a +1 and a -1 button?

When a model has a lot of layers, it can be difficult to get to a specific layer and look at layers around that one.

[hudbrog]

Arrow keys up and down on keyboard work as layer+/-