Get proposal to the nearest station when destination is outside of France

[divulgacheur]

In this example, the TGV_Maximize tool cannot find direct proposal because destination isn't in France.

 ./main.py Montpellier Bruxelles -q -t 1
mer. 15 déc. 2021 00:00:03
Direct journey from Montpellier to Bruxelles Midi (gare principale) (Belgique)
Let's try to split the journey from Montpellier to Bruxelles : 24 intermediate stations available

$ ./main.py Montpellier Lille -q -t 1
mer. 15 déc. 2021 00:00:50
Direct journey from Montpellier to Lille (toutes gares)
montpellier sud de france (09:10) → lille europe (14:24) TGV INOUI 5062 more than 10 seats remaining 
montpellier saint-roch (14:52) → lille europe (19:56) TGV 9864 more than 10 seats remaining 
montpellier sud de france (17:10) → lille europe (21:59) TGV INOUI 5182 more than 10 seats remaining 
Let's try to split the journey from Montpellier to Lille : 22 intermediate stations available

In the case the departure/arrival station is not located in France (see is_in_france()), use the closest station located in France to compute the proposals.