It'll be part of and owned by MetaContext, intending to replace
`meta_is_wayland_compositor()`, but place it in a new file for public
enums so that it can be used from wherever.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1861>
Tests that creating and starting a virtual screen cast monitor works,
and that at least one one buffer is processed.
Currently the content of the buffer isn't checked more than it can be
mmap():ed. Only MemFd buffers are tested for for now, as DMA buffers
would need a surfaceless EGL context to check properly.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>
The testing currently done is:
* Creating a virtual monitor succeeds and gets the right configuration
* Painting a few times results in the expected output
* Changing the content of the stage also changes the painted content
accordingly
* Destroying the virtual monitor works as expected
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1698>