guest_ime_modal_dialog opens a dialog with a 40 ms bound and never reads its
view: it captures input until the bound, then becomes Unshown, stops capturing,
ignores answers and lets the next dialog open. A dialog whose view was read
keeps capturing and can be answered long after the bound.
A guest test drives the session through its exported functions: refusal
without a presenter, with no buttons, with four buttons and with a focus or
cancel button out of range; focus clamping; confirm and cancel; close and
reset; the D-pad, the left stick and the Cross and Circle presses that only
count after the buttons were seen released; and the IME keyboard taking back
the view and the input until it releases them.
MarcZX10