Run key bindings on keyboard focus in

Run key bindings on keyboard focus in

This is mainly for X11's benefit; the common case is using Logo+S to
take a screenshot, where GNOME Shell has grabbed Logo, and replays the
event down to the nested compositor after S is pressed.  This means we
get an enter event with both Logo and S down, and even if Shell delivers
the key press event for S (which isn't mandatory, and not all window
managers do), then we never run the binding since notify_key realises
that S is already down and exits early.

Signed-off-by: Daniel Stone <daniel@fooishbar.org>