Add support for NAM files

[christoph-hart]

Hi Jatin,

how hard would it be to add support for parsing the NAM file format?

https://github.com/sdatkinson/NeuralAmpModelerCore

Just from a quick peek at both sources the required layers are almost there (except for the wavenet layer which seems like a high level abstraction of existing low level layers).

I would love to avoid adding too many neural network engines to my project so if you think it‘s doable I‘ll give it a shot.