[41] cursor-renderer/native: Add a means to disable HW cursors
When dealing with a faulty hardware or bugs in the driver, it might be interesting to force the use of software cursors for debugging purposes.
Add a debug environment variable MUTTER_DEBUG_DISABLE_HW_CURSORS to disable hardware cursors and force using software cursors.
Closes: #2046 (closed) Part-of: !2150 (merged)
(cherry picked from commit 56939abd)