`CollisionFlagMap` should be an interface & publish new pathfinder version please

[Jire]

CollisionFlagMap should be an interface as flags should not need to be exposed, this way API consumers can implement their own flag map from their existing flags if they chose.

[Tomm0017]

This is something I did weigh as an option. The issue is the performance hit from vtable lookup. CollisionFlagMap.get is one of the hottest code paths. Allowing abstractions would deal a heavy hit, when we can instead just provide a generic CollisionFlagMap to be used by consumers.