Only use route requests in plan mode

[jcoupey]

Issue

Fixes #444

Tasks

• Expose relevant info from OsrmRoutedWrapper
• Expose relevant info from ValhallaWrapper
• Expose relevant info from ORSWrapper
• Compute sparse matrices from HttpWrapper
• Compute sparse matrices from LibosrmWrapper
• Use sparse matrices from Input::set_matrices
• Make sure to run route requests in parallel
• Also store route geometries to populate solution
• Update CHANGELOG.md
• review

[jcoupey]

Still a UB problem with the edge case of multiple vehicles with same id.

[jcoupey]

It's expected that the benefit for this PR grows with the number of involved locations. Benchmarking shows a small benefit for very small plan requests (think just a few locations). But I observed roughly:

• a 2x speedup on real-life planning examples (routes in the tenths of stops);
• a 10x speedup on custom instances with several hundreds locations (actual gain depends on the number of vehicles).