meson: Merge args into a deep copy of the extra properties dict
meson: Merge args into a deep copy of the extra properties dict

GStreamer/cerbero,fluendo/cerbero,nirbheek/cerbero,atsushieno/cerbero,atsushieno/cerbero,atsushieno/cerbero,atsushieno/cerbero,GStreamer/cerbero,centricular/cerbero,GStreamer/cerbero,fluendo/cerbero,centricular/cerbero,centricular/cerbero,fluendo/cerbero,fluendo/cerbero,atsushieno/cerbero,centricular/cerbero,nirbheek/cerbero,GStreamer/cerbero,fluendo/cerbero,nirbheek/cerbero,centricular/cerbero,nirbheek/cerbero,GStreamer/cerbero