clients/presentation-shm: use xdg_shell instead of wl_shell

wl_shell is deprecated, and using xdg_shell allows the client to run on
compositors which do not implement the old protocol. Functionality
should be identical.

Signed-off-by: Astatos Aner <random.bored.human@gmail.com>
2 jobs for test in 1 minute and 24 seconds
Status Job ID Name Coverage
  Container Prep
passed #386618
container_prep

00:00:20

 
  Build
passed #386619
build-native-meson

00:01:04