Add option for mass_transit_data expiration
Add option for mass_transit_data expiration

If MASS_TRANSIT_LIVE_KEEP_DAYS configured, older data will be deleted
daily. Also, when starting up scheduler, start the live data fetch
job before the initial daily tasks run, to avoid missing live data
during that time.

aalto-trafficsense/regular-routes-server,aalto-trafficsense/regular-routes-server,aalto-trafficsense/regular-routes-server,aalto-trafficsense/regular-routes-server