Major upgrade Python Generator

[victorskl]

Context:

In libica-2.x,

We use 5.4.0 (LTS) throughout for ICAv2:

https://github.com/umccr-illumina/libica/blob/a735bb7/.openapi-generator/VERSION

And, 4.3.0 (LTS) throughout for ICAv1:

https://github.com/umccr-illumina/libica/blob/c320a6d/.openapi-generator/VERSION

Upgrade:

We shall upgrade this to latest generator 7.x when possible.

https://github.com/OpenAPITools/openapi-generator?tab=readme-ov-file#11---compatibility

Caveats:

This may likely break backward compatibility to sudden extent. It also depends on a generator choice.

[victorskl]

Also.

Explore alternative generators as replacement for more idiomatic, Pythonic, modern Python semantic.

Caveat is high risk with generated SDK code stability due to low adoption & user base.

Candidates:

• https://github.com/openapi-generators/openapi-python-client
• https://openapi-generator.tech/docs/generators/python-pydantic-v1/

[victorskl]

I am starting v3 package soon.

In v3 roadmap;

• I will retain current v2 as LTS purpose. (Just like v1 (LTS) <-> v2 transition)
• And, remove v1 packages completely.
• And, add deprecation marker to app package to redirect wrapica.