Jormungandr: refacto of the tests of the helpers
Jormungandr: remove journey with more fallback than the matching non_pt

for exemple with the walking, if the non_pt_walk has a duration of 12
minutes, the following journey will be masked:
    - walking 14min + TC
    - walking 8min + TC + walking 6min
jormungandr: the time for taking the bss must be counted in the bss duration
Jormungandr: even for non_pt journey we count the fallback duration with helpers

Else we didn't count the same thing, typically in bss we have walking
too
jormungandr: refacto in remove_non_optimal_journeys
Merge pull request #736 from kinnou02/remove_longer_fallback_than_non_pt

 Remove journey with more fallback than the matching non_pt