tests: add a test for wl_global_remove

This test makes sure that after wl_global_remove:

* The global_remove event is sent to existing clients
* Binding to the removed global still works
* A new client will not see the removed global advertised

Signed-off-by: Simon Ser <contact@emersion.fr>
1 job for global-unregister in 1 minute and 45 seconds (queued for 9 seconds)
Status Job ID Name Coverage
passed #588766