Add GeneratorRecipe

[tdb]

Add support for generator recipies. This was generated using a newer version of the OpenAPI tools, I think, because it looks slightly different. It does however work using the simple change in the example.

This brings the Python SDK more inline with the JS and Go versions which already have this feature.

I fully expect this to need modification by the devs before hopefully being incorporated. It's just my attempt to get the ball rolling, rather than just lazily asking for the feature to be added :-)