front: update propagation behaviour

[aschantraine]

This PR changes the behaviour of some propagation modes and creates a new one:

• fromDeparture: apply to an arrival, this mode doesn't change the waypoint departure anymore, the stop duration absorb the delta
• atThisWaypoint: apply to a departure, this mode doesn't change the stop duration anymore, the arrival absorbs the delta
• atThisTime: new mode that only change the edited time, the stop duration absorbs the delta (not the other time of the waypoint by opposition toatThisWaypoint)

Since there is no design for the new mode, I chose to keep the same icon as atThisWaypoint to express that only the edited point is touched. Feel free to suggest another icon.

The first 3 tabs of this doc are now implemented.

[Wadjetz]

lgtm

[SharglutDev]

Thank you for the PR ! Only tested it for now.

Tabs 1 & 2 from the doc works as expected 💪

Tab 3 (departure with stop):

• atThisTime

The delta displayed doesn't match what's asked (the new schedule are ok though):

It seems to count : old value - (new value + current stop).
This is also not the expected delta for the atThisWaypoint option (23:25 instead of 23:35)

• atThisWaypoint

For this one, I'm a bit confused regarding what it's expected because it seems like the delta should represents what will change for the arrival ? (that's is asked for the '18:10' test) 😵‍💫

But we see this:

The rest of tab 3 is good ✅

[SharglutDev]

Lgtm and tested, great work !

[SharglutDev]

@maelysLeratRosso regarding my above comment on deltas, we discussed with @aschantraine and the app behavior looked fine. Could you double check these two cases delta to see if it's really the value you expect ? :) If yes, you can find a fix in a followup PR.