Display CO2 emissions information for itineraries

[hbruch]

For each itinerary, stadtnavi should show the CO2 emissions per trip.

This functionality has been implemented by upstream already and should be backported to stadtnavi.

If code needs to be changed to get it working, consider bringing stadtnavi closer to upstream.

OTP on https://api.dev.stadtnavi.eu/ already has been configured to return the co2emissions.

The following commits introduced to core functionality to upstream digitransit (Note: the code might have been adapted in later commits, please check).

HSLdevcom@92eb64d
HSLdevcom@15a09fd

[andreashelms]

@hbruch
Do we only need this component from upstream?

Or also the compared emissions produced by a car?

[hbruch]

When is this component shown? and which content is linked there? We should add a link to an explaining text as well, IMHO an external page. @stadtnavimanager could you create a page in the stadtnavi CMS where we explain the calculations?

[andreashelms]

Here is an example. The component is shown at the bottom of the itinerary tab:
https://reittiopas.hsl.fi/reitti/V%C3%A4nrikki%20Stoolin%20katu%2010b%2C%20Helsinki%3A%3A60.17670743114979%2C24.926841259002686/Suvilahdenkatu%201%20B%2C%20Helsinki%3A%3A60.1870677971542%2C24.967203140258793/0?arriveBy=false&fromMap=origin&locale=en&time=1732015708.425