Improvements to maneuver override processing

[mjjbell]

Issue

This change unblocks the osrm-extract debug build, which is currently failing on a maneuver override assertion.

The processing of maneuver overrides currently has three issues:

• It assumes the via node(s) can't be compressed (the failing assertion)
• It can't handle via-paths containing incompressible nodes
• It doesn't interop with turn restrictions on the same path

Turn restrictions and maneuver overrides both use the same from-via-to path representation. Therefore, we can fix these issues by consolidating their structures and reusing the path representation for turn restrictions, which already is robust to the above issues.

This also simplifies some of the codebase by removing maneuver override specific path processing.

There are ~100 maneuver overrides in the OSM database, so the impact on processing and routing will be minimal. But who knows, with improved support, it might encourage further adoption.

Tasklist

• [x] CHANGELOG.md entry (How to write a changelog entry)
• [ ] update relevant Wiki pages
• [x] add tests (see testing documentation
• [ ] review
• [ ] adjust for comments
• [ ] cherry pick to release branch

Requirements / Relations

Fixes #6126