Add HDRP/LWRP support

[AndrewRH]

Currently the ApplyToMaterial/ApplyToMesh scripts don't work correctly. This is due to materina.mainTexture not working with HDRP, so it needs to be changed eg:

				//_material.mainTexture = texture;
				_material.SetTexture("_BaseColorMap", texture);

Have to see if anything else needs changing too.

[jsd-within]

Testing the free version of the plugin in HDRP yesterday (6/13/2019) I found that the antialiasing dropdown had no effect and that checking the motion blur checkbox prevented successful export, even at very low resolutions. However, I was able to successfully export without those options turned on.

[stale[bot]]

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