Add 3D models for XAD seriers JST connectors. See pull request in footprints: KiCad/kicad-footprints#2310

Thanks for creating a pull request to contribute to the KiCad libraries!
Remember you must be the legal owner of the 3D model! Models downloaded from a manufacturers website cannot be accepted.

To speed up integration of your PR, please check the following items as you complete them:

• A screenshot of the model(s) aligned with KiCad footprint(s)
• Source files are contributed on the apropriate location
  • Link to the package3d-source pull request or to the script pull request
• Step model submitted in 1:1 scale
• WRL model submitted in 1:2.54 scale
• 3D model alignment checked against KiCad footprint
• WRL model uses correct material properties
• Geometry check performed on the model

Be patient, we maintainers are volunteers with limited time and need to check your contribution against the datasheet. You can speed up the process by providing all the necessary information (see above).