feat(popup): conventional number inputs (not just range sliders)

[WofWca]

or, with border and background set to none:

Useful if you want to increase, say, the sounded speed just a notch, or when you want some precise value. Some may find the slider a bit clunky. And it has been requested by users.

Although the default increment/decrement buttons may be a bit too small, so maybe need to add custom ones. Another sketch I got:

Maybe make it optional.