Vehicle type grouping in the visualization

[richfab]

What is the issue and why is it an issue?

When visualizing this feed from Entur, the 'car' vehicle type is duplicated many times.

Instead 'car' should be grouped into one vehicle type.

How to reproduce: https://gbfs-validator.mobilitydata.org/visualization?url=https%3A%2F%2Fapi.entur.io%2Fmobility%2Fv2%2Fgbfs%2Fotto%2Fgbfs%09

Observed	Expected

Please describe some potential solutions you have considered (even if they aren’t related to GBFS).

I think the grouping should be done on the form_factor field from the vehicle_types.json file (if it's not already the case).

[richfab]

Tagging @testower (feed producer) and @tdelmas (visualizer developper) for visibility.