wayland: Move focus window logic up to WaylandInputDevice

WaylandWindow also needs this information for input grab.

Signed-off-by: Tiago Vignatti <tiago.vignatti@intel.com>

The patch was imported from https://github.com/tiagovignatti/ozone-wayland/
as of commit id https://github.com/tiagovignatti/ozone-wayland/commit/ae512bf9bc914ceec6d916f52f36bfc2df495d18.

Replaced pointer usage with window handle and include order fix.

Signed-off-by: Kalyan Kondapally <kalyan.kondapally@intel.com>