rm padding that was misaligning button view sprite

This padding existed to make outline-on-hover work in edit view, but edit view is pretty obsolete now.

[#52562895]
Fix inconsistent color of range highlight.

[#52551887]
More-robust metrics for sizing submit button

[#52344215]
Stop Chrome for Android keyboard popping up, pt. 1

[#52416165]
Stop Chrome for Android keyboard popping up, pt. 2

Start/Stop/Reset buttons need to defocus any focused textarea; removing the SC.ButtonView's evt.preventDefault doesn't do the trick.

[#52416165]