Draft: Meson: Add gstreamer-full.wrap fallback

While playing with this I encountered a few issues:

• !4487 (closed)
• !4482 (closed)
• Ideally we should make a minimal build of GStreamer using -Dauto_features=disabled
  • Meson does not allow setting auto_features=disabled only on GStreamer and its subprojects, so it will apply also to GTK and any other subproject. Maybe not a big deal.
  • When using -Dauto_features=disabled we have no way from GTK to enable some specific GStreamer features (gl, matroska, etc), it has to be done by the user using -Dgst-plugins-base:gl=enabled. Meson does not allow doing dependency('gstreamer-1.0', default_options: ['gst-plugins-base:gl=enabled']), it is only allowed to set default options on the subproject, not sub-subproject.
• Would make sense to static link GStreamer and its plugins in this case, but unfortunately setting dependency('gstreamer-1.0', default_options: ['default_library=static']) does not apply to sub-subprojects, so gst-plugins-base (etc) are still built shared.