Add support for JT file format

[PolygonalSun]

Add JT importer.

JT (Jupiter Tessellation) is an ISO-standardized 3D data format and is in industry used for product visualization, collaboration, CAD data exchange, and in some also for long-term data retention.

Tasks

• Investigate the JT format and determine what features to support / what can convert to glTF. At a minimum, geometry and textures should be parsed and converted.
• Implement parser to convert JT to Asset3D. See the OBJ importer as an example.