[navigation system/pathfinding] (low priority) Ability to update navmesh during runtime

Could take form as a Haxe function as well as a logic node that lets you create a new navmesh or update an existing navmesh based on meshes in a specified collection

Start by locating the navigation system/pathfinding entry points and the runtime logic-node integration. Define completion as a Haxe function and logic node that can create a navmesh or update an existing one from meshes in a specified collection.

Written by the indexing model from the issue text.