Support for Agents of different sizes

[Barsonax]

Summary

Currently there is a clearance float for this but it's unused. The Pathfinder should be able to take the agents size into account.

This could be implemented by adding a list of clearances per node with a clearance value and a collisionmask. The clearance will be the true clearance which can be found here: https://aigamedev.com/open/tutorials/clearance-based-pathfinding/. This will all be precalculated.

The exact clearance will be calculated at runtime by getting all the clearances that have a collision with the collisionlayer provided and then taking the smallest one.

This should provide a balance between memory usage and cpu usage as its not practical to store all possible combinations of clearances and collisionlayers beforehand.

[Barsonax]

Implemented in PAX-8