tests: Make tests components have ownership chains as well

This means we can eliminate the use of scattered singletons that isn't
added by the tests or the test framework itself.

tests: Don't get backend from old singleton getter

Either use the ownership chain, or the explicit test context instance
pointer.

tests/wayland: Pass context to test client constructor

So that we can get the Wayland compositor directly from the context.

tests: Don't get display from singleton

tests/client: Make test client carry a context pointer

tests/runner: Have test cases carry a context pointer

tests/wayland/test-driver: Get backend from context

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2718>

src/backends/meta-renderer-view.h

@@ -23,12 +23,14 @@
 #include "backends/meta-stage-view-private.h"
 
 #define META_TYPE_RENDERER_VIEW (meta_renderer_view_get_type ())
+META_EXPORT_TEST
 G_DECLARE_FINAL_TYPE (MetaRendererView, meta_renderer_view,
                       META, RENDERER_VIEW,
                       MetaStageView)
 
 MetaMonitorTransform meta_renderer_view_get_transform (MetaRendererView *view);
 
+META_EXPORT_TEST
 MetaCrtc *meta_renderer_view_get_crtc (MetaRendererView *view);
 
 #endif /* META_RENDERER_VIEW_H */