Add Layer Definition File and 3D Model to the resource API

[Xpirix]

This is a proposed change for #280

Changes summary

• Return Layer Definition and Wavefront (3D Model) in the resource API
• Update unit test

[ismailsunni]

So, Wafefront is the 3D model? May I know why is it called like that? Otherwise, it looks good for me

[Xpirix]

I think it refers to the pip package the app used to manage 3D models which is called PyWavefront. It's related to #182.

[ismailsunni]

@Xpirix perhaps, it's better to have different terminology for the resource type since it's not self explanatory. It is also more on the technical term, not the context. See similar comment regarding this #202 (comment). I guess 3DModel is clearer.

[Xpirix]

Yes, that makes more sense. I've changed Wavefront to 3DModel for the resource API for now. Also, I will create an issue to replace all Wavefront occurrences in the code with 3DModel.

[ismailsunni]

Thanks @Xpirix !