This tests both a sequence being claimed early to be then denied
(and handled deeper in propagation chain), and a sequence being
claimed late in the capture phase (and thus being cancelled deeper
in the propagation chain)
Before this change, a sequence being claimed deep in the event propagation
chain would make the sequence go denied on every ancestor, regardless of
previous state.
To make things more consistent, only deny the sequence if it was previously
claimed, so the behavior is the same for gesture groups within the widget
than for those outside the widget.
The gestures testsuite has been updated to reflect this new behavior.
It might happen that a gesture claims a sequence before any other gesture
in its group even handled a single event from that sequence. In that case,
ensure the state is set accordingly right when the sequence is handled in
those.
The "group" gesture testcase has been updated to observe this behavior.
