Port tests to use API such as cogl_framebuffer_push_matrix() instead of
cogl_push_matrix() all over the Clutter tests, with one exception:
cogl_polygon(). It'll be ported over in a separate commit, as it is less
straight forward.
Implicitly set CoglMaterial properties are changed to explicitly created
and destructed CoglPipelines with the equivalent properties set.
cogl_push|pop_framebuffer() is replaced by explicitly passing the right
framebuffer, but tests still rely on cogl_get_draw_framebuffer() to get
the target framebuffer.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/935