Wrap change/delete window property request handlers

Preparation for the following change.

v2:
* Add comments explaining what the wrappers are wrapping.
* Use global amdgpu_property_vectors_wrapped to keep track of whether
  the vectors need to be (un)wrapped, for robustness against VRR being
  enabled in some but not all AMDGPU screens.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>