tests: wl_pointer enter corners and button tests
This implements a way-assay interface for pointers with a WLCS backend alongside a few tests.
I used f64
for window coordinates mostly to avoid casting for pointer control in the tests, wlcs::position_window_absolute
uses isize
. Perhaps a generic bound with TryInto<i32>
would make sense for WLCS?
Edited by Colin Kinloch