HPA Pathfinding

[bearU369]

Relevant post: Hiveworkshop

I closed the PR after some time thinking that maybe we could make use of HPA to perform small series of pathfindings between small distances for units to seamlessly keep moving while preventing them to freeze due the pathfinding is still being processed behind the scene when attempt to move over to a large distance. I'm wondering how this will be integrated alongside CPathfindingProcessor to maintain the stateful processing of the pathfinding.