AR visualization

[pekkaran]

Also @kaatrasa

This PR adds example mesh and point cloud visualizations for the SDK Mapping API. It works live on OAK-D and with recorded sessions.

The example is invoked through mapping_ar.py which internally uses two separate classes in the mapping_ar_renderers/ directory:

├── mapping_ar.py
└── mapping_ar_renderers
    ├── mesh.py
    ├── mesh.frag
    ├── mesh.vert
    ├── point_cloud.py
    ├── point_cloud.frag
    └── point_cloud.vert

The commits are probably best viewed together.

Requires SDK features not released yet, perhaps should not be merged before the next release.