`is_momentary` becomes `position_only` on both the sense and the cursor,
inverted so it reads as what it tests.
A widget the cursor has left was being handed a blanked cursor so its
press senses would not match. `should_run` now skips non-position senses
when the pointer is not inside, which is the same rule without lying
about the input: the widget still gets the real cursor with its hover
ending.
`consumes` loses its `momentary` argument, since the cursor answers that
itself.