Improve three debug helpers

[isaac-mason]

NavMeshHelper needs several improvements, it's not as useful as the visualisations in RecastDemo.

[isaac-mason]

Consider just implementing duDebugDraw and using recastnavigation's debugging utilities: https://github.com/recastnavigation/recastnavigation/blob/cd898904b72a300011fbb24d578620bafa08ef2c/DebugUtils/Include/DebugDraw.h#L34

[isaac-mason]

Some progress implementing duDebugDraw:

[isaac-mason]

https://github.com/isaac-mason/recast-navigation-js/tree/feat/duDebugDraw

[isaac-mason]

duDebugDrawRawContours

[isaac-mason]

https://recast-navigation-js.isaacmason.com/?path=/story/debug-three-debug-drawer--poly-mesh

[isaac-mason]

0.25.0 of recast-navigation/three has a new DebugDrawer class that supports:

• Recast debug draw utilities:
  • debugDrawHeightfieldSolid
  • debugDrawHeightfieldWalkable
  • debugDrawCompactHeightfieldSolid
  • debugDrawCompactHeightfieldRegions
  • debugDrawCompactHeightfieldDistance
  • debugDrawHeightfieldLayer
  • debugDrawHeightfieldLayers
  • debugDrawRegionConnections
  • debugDrawRawContours
  • debugDrawContours
  • debugDrawPolyMesh
  • debugDrawPolyMeshDetail
• Detour debug draw utilities:
  • debugDrawNavMesh
  • debugDrawNavMeshWithClosedList
  • debugDrawNavMeshNodes
  • debugDrawNavMeshBVTree
  • debugDrawNavMeshPortals
  • debugDrawNavMeshPolysWithFlags
  • debugDrawNavMeshPoly

Still a WIP - some TileCache methods need to be exposed to support visualising TIleCache intermediates.

Creating debug drawer implementations for other graphics libraries is doable, but there's some opportunities to make it more straightforward.

[GGAlanSmithee]

duDebugDrawRawContours

this is amazing!

[isaac-mason]

The debug helpers can still use more improvement, and TileCache helpers should get exposed but the helpers released in v0.25.0 were a huge leap forward.

Closing this issue and opening a new one for TileCache helpers.