tracker-extract: gstreamer: use nfo:VectorImage for image/svg+xml
tracker-extract: gstreamer: use nfo:VectorImage for image/svg+xml

Fixes NB#211926

hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,hoheinzollern/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,outofbits/tracker,hoheinzollern/tracker,outofbits/tracker,hoheinzollern/tracker