Meson: gst-build cannot be used as subproject because of add_global_arguments()

As an experiment, I tried to build GTK4's gstreamer media backend on Windows by adding a gst-build.wrap. It fails because gst-build uses add_global_arguments() when the compiler is MSVC. We should try to find another way of doing that...

Other than that, it worked! 49 subprojects, 9700 ninja targets... https://imgur.com/a/KxiMJw9.

[wrap-git]
url=https://gitlab.freedesktop.org/gstreamer/gst-build.git
revision=master

[provide]
dependency_names=gstreamer-player-1.0