Investigate using progenitor to generate the SDK

[demeringo]

Current SDK is difficult to generate for API V0.2x and likely future V0.3.x (see #6 )

Describe the solution you'd like

Test if generating the sdk with progenitor could ease life (avoid manual fixes on the generated code).

https://github.com/oxidecomputer/progenitor

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context

Using a different generator is a breaking change, it will imply to update the code using it (like cloud-scanner).