tests: Teach QCOMPARE() printing certain GStreamer values
tests: Teach QCOMPARE() printing certain GStreamer values

comicfans/libqtgstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,nasserGanjali/QtGStreamer,ylatuya/qt-gstreamer,dejunk/gstreamer,knuesel/qt-gstreamer,nasserGanjali/QtGStreamer,ylatuya/qt-gstreamer,iperry/qt-gstreamer,iperry/qt-gstreamer,comicfans/libqtgstreamer,dejunk/gstreamer,GStreamer/qt-gstreamer,nasserGanjali/QtGStreamer,tswindell/qt-gstreamer,detrout/qt-gstreamer,iperry/qt-gstreamer,GStreamer/qt-gstreamer,detrout/qt-gstreamer,tswindell/qt-gstreamer,knuesel/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,detrout/qt-gstreamer,ylatuya/qt-gstreamer,knuesel/qt-gstreamer,tswindell/qt-gstreamer,freedesktop-unofficial-mirror/gstreamer__qt-gstreamer,dejunk/gstreamer,comicfans/libqtgstreamer,GStreamer/qt-gstreamer