clutter: Switch to storing device->actor associations in ClutterStage

As planned and prepared with the last commits, let ClutterStage take
care of tracking input devices and their respective actors. This means
we now can remove the old infrastructure for this from
ClutterInputDevice.
13 jobs for device-actors-stage
Status Job ID Name Coverage
  Review
manual #1047481
manual
check-commit-log
manual #1047482
manual
check-merge-request
 
  Prepare
created #1047484
aarch64
build-fedora-container@aarch64
created #1047483
build-fedora-container@x86_64
 
  Build
created #1047486
aarch64
build-mutter@aarch64
created #1047485
build-mutter@x86_64
created #1047488
build-without-native-backend-and-wayland@x86_64
created #1047487
build-without-opengl-and-glx@x86_64
 
  Test
created #1047491
can-build-gnome-shell@x86_64
created #1047490
aarch64
test-mutter@aarch64
created #1047489
test-mutter@x86_64
 
  Coverage
created #1047493
aarch64
test-mutter-coverage@aarch64
created #1047492
test-mutter-coverage@x86_64