search: Check for either tracker 2.x or 3.x schemas

Carlos Garnacho requested to merge wip/carlosg/search-tracker3 into master

The Tracker3 schema points to the same dconf path and is backwards compatible with Tracker 2.x settings. Check for either here, with a preference to Tracker 3.x.

Eventually, Tracker 2.x will be fully phased out, and this will not be necessary.

Fixes: #1173 (closed)

Merge request reports