Further Work on Partitioning

[MoKob]

To not keep partitioning on a separate branch any longer, @daniel-j-h and I would like to move further tasks into post-merge land.

Multiple groups of issues can be worked on further:

Optimisation

• Optimise balance for cuts: .25 ratio may result in .25 / .75 cuts (somewhat possible via annotation tool)
• Transform partition ids to edge based graph, outlined in Implement Inertial Flow Partitioner #3205
• Border cases in the partition should probably be resolved in a smarter way (ebg - part I) (@daniel-j-h -- could you add some more context here ?)

Documentation

• document the .osrm.cnbg .osrm.nbg_to_ebg files in our Wiki file listing
• document the new osrm-partition tool, its parameters and what it does

Testing

• unit test edge-based-graph loader
• unit test annotation tool

Output generation

• Ebg loader could benefit from a refactored with what the contractor does (if possible) Covered by general graph refactor.
• The Annotation tool can be augmented to output partition information for MLD
• We need to write out the new transformed edge based graph for customize ( ebg - part II)

[TheMarex]

Remaining tasks are not actionable or covered by other issues.