libtracker-data: remove unneeded fallback methods to use glib as unicode support
libtracker-data: remove unneeded fallback methods to use glib as unicode support

We already require either libunistring or libicu, so the glib-based fallback
methods will actually never be used.

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