tracker-needle: Ensure consistency of the model information and its internal data
tracker-needle: Ensure consistency of the model information and its internal data

Children were being added one by one, but the iter functions already
handled the results array as if it was fully populated. This fixes
the treeview disparity warnings.

Also, proper timestamps are now set in the treeiters.

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