[NavMesh Pathfinding] Filter obstacles

[D8H]

Description

• A feature request on this feature: NavMesh pathfinding behavior #2856
• Every object may not have the same movement constraints. For instance
  • ground vehicles collide to building
  • flying objects could collide only to mountains
  • boats can only go where there is water

Functional solution

• Add a parameter on the obstacle behavior to name a group of obstacles (or use an object/group instead?).
• Add a parameter on the pathfinding behavior to filter the obstacles.

Technical solution

• There will be one NavMesh per used filter.