Display metro exits (and name/number) on the map and possibly route guides

[rugk]

Acknowledgments
Please check the following boxes with an x if they apply:

• The feature I want to propose would be useful for the majority of users, not only for me personally.
• I am aware that Transportr is mostly developed by one person in their unpaid spare time.
• I can help myself to get this feature implemented or know someone who wants to do it.
• If I want to add support for a new region or country, I checked that this is already available in public-transport-enabler and know the process described on the Transportr homepage.

Is your feature request related to a problem? Please describe.
I'm always frustrated when I am travelling with the metro, have multiple exists and take a wrong (not optimal) one. Instead, I would like to take the correct one.

Signs usually say the street and an exit number, but a non-local and with multiple streets the street name does nor help me much (more below), as such knowing the exit number I need to take would help a lot.

Specifically this is how such a navigation looks like in Paris:

Describe the solution you would like
Display the mwtro exit and exit name+number somewhere, either directly on the map and/or in the routing guide.

Describe alternatives you have considered

• How do you solve this issue now with Transportr or other apps? → go out "random" or where most people exit (or use another app like Osmand to find the exit) or try the street names, which are also shown on the exits and estimate what is the one they want (that last thing is hard for many streets and crossings like in Paris, so exit numbers are way easier IMHO)
• Attach any examples, screenshots, or screen recordings from other apps that help us to better understand the idea.

Osmand displays it in brackets next to the name:

Additional context
Similar issue for OrganicMaps: organicmaps/organicmaps#5110

[Altonss]

This enhancement would really make sense, and I would love to see this implemented. Unfortunately a lot of other issues/bugs have a higher priority, and we need to tackle those first!
But we could come back to this once we have more time. Also this issue is a hard one, and appart from OSM data, I don't see where we could get the information from. This topic has already been discussed in an old issue here: #310