Revert "pointer: Repick after the focused surface is destroyed"

This reverts commit e496ed50d6b127a57cfc189bad19a32564fde46b.

This was incorrect. wl_surface_destructor actually does the full repick
-- doing it here is dangerous, because the destroy listeners actually
run *before* the destructor, not after, so the surface is still alive.
Revert "wayland-pointer: Just use the pointer actor instead of doing a full repick"

This reverts commit 33acb5fea07c83236f254456d11d34e2c7671719.

The issue here is that the pointer actor does not actually get reset
when the actor's reactivity changes, so we end up with stale picks after
actors are destroyed.

I have a local patch to Clutter for this, but I don't have time to
submit it upstream, so let's just use the ugly code for now.