Bulk schedule editing for train lines

[bangetto]

Is your feature request related to a problem? Please describe.
Currently there's no way to easily edit the schedule of a group of trains

Describe the solution you'd like
Since the mod already have train groups we could reuse them to bulk edit schedules (or maybe add a separate option)

Describe alternatives you've considered
make train schedules on stations only apply to certain trains (like a name filter)

Additional context
technically possible, but the train needs to stop on his own separate station which makes oversized stations or unexpected stops