SIRI-ET - GTFS-RT compare - flag / remove not active trips

- in [./apps/siri-et-compare-gtfs-rt](https://github.com/openTdataCH/showcases/tree/develop/apps/siri-et-compare-gtfs-rt)
- flag / remove trips from SIRI-ET which are outside of `now` 
  - TBD what `now` means
  -  in section `SIRI-ET with GTFS-static but no GTFS-RT:`