Add python OpenRPC generator

[link2xt]

[link2xt]

There is an issue that all BTreeMap and HashMap are converted to dict[Any, ...] because of https://github.com/GREsau/schemars/issues/235

[link2xt]

Now there are dataclasses for every type which are automatically converted to JSON. Next step is to generate functions that convert the result they get into dataclasses. There is a related question with link to libraries at https://stackoverflow.com/questions/69933251/how-to-convert-a-json-structure-into-a-dataclass-object-tree but hopefully they are not needed.