When a state change happens, ensure the keyboard is hidden. When a
keyboard is hidden, ensure all pending timers our cleared. When
resetting scrollView, ensure it’s only doing it when it has to.
For testing: #1670#2192
Overhaul of the tap system so the keyboard does not cover up focused
inputs, correctly bring up the keyboard on text input focus, disabling
focus during scroll, disabling clicks after a hold then scroll,
removing 300ms delay without additional event handlers on each element,
etc. Refactored the tap/click/scroll/activator events for more
testability, along with adding more tests.