refactor: migrate wheelchair attributes storage to encoded values (WIP)

[jarinox]

Pull Request Checklist

• 1. I have [rebased][rebase] the latest version of the main branch into my feature branch and all conflicts
  have been resolved.
• 2. I have added information about the change/addition to functionality to the CHANGELOG.md file under the
  [Unreleased] heading.
• 3. I have documented my code using JDocs tags.
• 4. I have removed unnecessary commented out code, imports and System.out.println statements.
• 5. I have written JUnit tests for any new methods/classes and ensured that they pass.
• 6. I have created API tests for any new functionality exposed to the API.
• 7. If changes/additions are made to the ors-config.json file, I have added these to the [ors config documentation][config]
  along with a short description of what it is for, and documented this in the Pull Request (below).
• 8. I have built graphs with my code of the Heidelberg.osm.gz file and run the api-tests with all test passing
• 9. I have referenced the Issue Number in the Pull Request (if the changes were from an issue).
• 10. For new features or changes involving building of graphs, I have tested on a larger dataset
  (at least Germany), and the graphs build without problems (i.e. no out-of-memory errors).
• 11. For new features or changes involving the graphbuilding process (i.e. changing encoders, updating the
  importer etc.), I have generated longer distance routes for the affected profiles with different options
  (avoid features, max weight etc.) and compared these with the routes of the same parameters and start/end
  points generated from the current live ORS.
  If there are differences then the reasoning for these MUST be documented in the pull request.
• 12. I have written in the Pull Request information about the changes made including their intended usage
  and why the change was needed.
• 13. For changes touching the API documentation, I have tested that the API playground [renders correctly][api].

Fixes #993

Information about the changes

• Key functionality added: migrates the storage of WheelchairAttributes from external storage to encoded values
• Reason for change: cleanup

[sonarqubecloud]

Quality Gate passed

Issues
15 New issues
0 Accepted issues

Measures
0 Security Hotspots
85.4% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[jarinox]

@aoles As you proposed, I created some basic new parsers based on the original WheelchairGraphStorageBuilder, and they are working fine. I then enabled the attributes in my rewritten parsers one by one until the tests failed or the old edge delivered different results than the new one.

Through that process, I eliminated the remaining issues with the new parsers. They are now all enabled and produce the exact same results as the old ones. I've also started cleaning up the deprecated code.

One remaining question: What is the best way to expose kerbHeightOnlyOnCrossing as a configurable property?