Revert "[NONE] Add snippet suitable to hunt down a rendering bug when using ScrollPaneEx."

This reverts commit 0cf299d96f2fb862c7f431bd3cd0788a3e0d0a11.
[NONE] Provide a binding for the scrollable bounds of a ScrollPaneEx.
[NONE] Replace ScrollPane with ScrollPaneEx.
[NONE] Do not scroll when a modifier key is pressed.
[449870] Zoom relative to the mouse pointer location.
[NONE] Update ViewportModel on scrollbar changes.