Update to 3.1.0.rc, based on earlier tracker3-miners packaging
    
    This effectively retires old tracker-miners 2.x and moves tracker-miners
    3.x from tracker3-miners package to tracker-miners package as we no
    longer have any packages left that require tracker 2.x.
    
    I've reused tracker3-miners packaging here exactly as it was, and only
    updated the package name to tracker-miners + added obsoletes and
    provides to keep the upgrade path.
    
    With this, we can retire the separate tracker3 and tracker3-miners packages.