Add StreetDetailsService for storing level and incline information for edges

[VillePihlava]

Summary

This PR adds the StreetDetailsService which is used for storing level and incline information for edges. A build config field is provided to enable/disable storing level and incline info for escalators and stairs. This PR also adds info about stairs, escalators, and elevators to the walksteps of a leg of the GTFS GraphQL API.

I also did some refactoring where I felt it was necessary, e.g. in EscalatorProcessor and OsmModule.

Issue

Closes #6829

Unit tests

New tests:

• EdgeLevelInfoTest.java - a new test class for tests related to storing incline/level information for elevators, escalators, and stairs
• OsmWayTest.java - small changes to osm way testing
• StatesToWalkStepsMapperTest.java - test related to escalators/stairs/elevators
• GraphQLIntegrationTest.java - changing steps test by adding ElevatorUse, EscalatorUse, and StairsUse

Documentation

• Javadoc
• Build config field summary

[leonardehrenfried]

I probably missed something, but I would like to know why half the features are created in the WalkStepMapper and the other half isn't.

Let's discuss in the dev meeting.

[VillePihlava]

I added the ElevatorUse. I still need to create a test for OsmModule, add a nice name for elevatoralightedge, and solve the merge conflicts. After this, this should be ready-for-review.