libtracker-common: Improve ISO 8601 time parsing
libtracker-common: Improve ISO 8601 time parsing

Properly support local time and accept milliseconds, fixes NB#125763.

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