cogl: Install cogl-trace.h and include from cogl.h

This is so that cogl-trace.h can start using things from cogl-macros.h,
and so that it doesn't leak cogl-config.h into the world, while exposing
it to e.g. gnome-shell so that it can make use of it as well. There is
no practical reason why we shouldn't just include cogl-trace.h via
cogl.h as we do with everything else.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1059

src/core/workspace.c

@@ -40,7 +40,7 @@
 
 #include "backends/meta-backend-private.h"
 #include "backends/meta-logical-monitor.h"
-#include "cogl/cogl-trace.h"
+#include "cogl/cogl.h"
 #include "core/boxes-private.h"
 #include "core/meta-workspace-manager-private.h"
 #include "core/workspace-private.h"