wsi/x11: Disable vk_xwayland_wait_ready by default and refactor minImageCount selection.
wsi/x11: Rewrite logic for how we consider minImageCount.
MAILBOX reduced from 5 to 4 to be more inline with WL.
With xwayland_wait_ready = false now being the default, add some extra consideration for non-FIFO present modes. Add a lengthy rationale for why minImageCount = 3 is exposed on Xwl.
Since Venus is special, the wait_ready logic is kept there for now.
Edited by Hans-Kristian Arntzen