[FEATURE] StackView shouldn't layout and draw hidden layers

**Is your feature request related to a problem? Please describe.**
StackView lays out and draws all layers, even if they are not visible. If you have a Stack of a bunch of fullscreen layers, it doesn't make any sense to layout and draw any but the front layer. However, StackView always calls layout/draw on all layers. You need a custom view and some hacks (like checking if the printer is focused in draw) to avoid this.

**Describe the solution you'd like**
StackView should be clever enough to not call layout/draw on layers that are not being shown.

**Describe alternatives you've considered**
As above, custom views can hack around this.