Add a non-blocking version wrapper for wl_display_dispatch_pending.
This uses roughly the same logic as Wayland_PumpEvents in SDL.
Noticed this when investigating T100855.
Note that performing a round-trip doesn't seem necessary from looking
into QT/GTK & SDL event handling loops.
Some of the previous commits in Wayland related code added use
of this function, but did not update the dynamic loader. This
broke compilation of configurations which use dynamic loader
for Wayland (which is the official way oh how Blender is built).
Add intern/wayland_dynload which is used when WITH_GHOST_WAYLAND_DYNLOAD
is enabled (off by default). When enabled, systems without Wayland
installed will fall back to X11.
This allows Blender to dynamically load:
- libwayland-client
- libwayland-cursor
- libwayland-egl
- libdecor-0 (when WITH_GHOST_WAYLAND_LIBDECOR is enabled).
