tests: multifile: increment tests to check for multifile messages
tests: multifile: increment tests to check for multifile messages

Also verify that the multifilesink file messages are being correctly
posted to the bus

Kurento/gst-plugins-good,rawoul/gst-plugins-good,ijsf/OpenWebRTC-gst-plugins-good,Kurento/gst-plugins-good,StreamUtils/gst-plugins-good,hizukiayaka/gst-plugins-good,chamois94/gst-plugins-good,sebras/gst-plugins-good,StreamUtils/gst-plugins-good,vatavuserban/gst-plugins-good,ijsf/OpenWebRTC-gst-plugins-good,pexip/gst-plugins-good,hizukiayaka/gst-plugins-good,BigBrother-International/gst-plugins-good,chamois94/gst-plugins-good,stfl/gst-plugins-good,ijsf/OpenWebRTC-gst-plugins-good,shelsonjava/gst-plugins-good,kittee/gst-plugins-good,ijsf/OpenWebRTC-gst-plugins-good,freedesktop-unofficial-mirror/gstreamer__gst-plugins-good,chamois94/gst-plugins-good,StreamUtils/gst-plugins-good,stfl/gst-plugins-good,BigBrother-International/gst-plugins-good,froggatt/gst-plugins-good-m,GStreamer/gst-plugins-good,BigBrother-International/gst-plugins-good,rawoul/gst-plugins-good,pexip/gst-plugins-good,shelsonjava/gst-plugins-good,GStreamer/gst-plugins-good,ikonst/gst-plugins-good,rawoul/gst-plugins-good,GrokImageCompression/gst-plugins-good,ikonst/gst-plugins-good,ikonst/gst-plugins-good,ikonst/gst-plugins-good,BigBrother-International/gst-plugins-good,kittee/gst-plugins-good,StreamUtils/gst-plugins-good,vatavuserban/gst-plugins-good,hizukiayaka/gst-plugins-good,rawoul/gst-plugins-good,pexip/gst-plugins-good,freedesktop-unofficial-mirror/gstreamer__gst-plugins-good,stfl/gst-plugins-good,Kurento/gst-plugins-good,froggatt/gst-plugins-good-m,chamois94/gst-plugins-good,freedesktop-unofficial-mirror/gstreamer__gst-plugins-good,froggatt/gst-plugins-good-m,GrokImageCompression/gst-plugins-good,hizukiayaka/gst-plugins-good,pexip/gst-plugins-good,freedesktop-unofficial-mirror/gstreamer__gst-plugins-good,kittee/gst-plugins-good,stfl/gst-plugins-good,shelsonjava/gst-plugins-good,sebras/gst-plugins-good,froggatt/gst-plugins-good-m,Kurento/gst-plugins-good,vatavuserban/gst-plugins-good,GrokImageCompression/gst-plugins-good,GStreamer/gst-plugins-good,GrokImageCompression/gst-plugins-good,vatavuserban/gst-plugins-good,shelsonjava/gst-plugins-good,sebras/gst-plugins-good,Kurento/gst-plugins-good,sebras/gst-plugins-good,GStreamer/gst-plugins-good,pexip/gst-plugins-good,kittee/gst-plugins-good