Konnect entities: API spec and code generator for scaffolding and controller code

[pmalek]

Problem statement

Support for Konnect entities in the operator (#370) shipped in 1.4.0 introduced a lot of code that is manually developed and maintained. This could potentially be generated.

This issue tracks the effort of designing the spec and generator that uses the spec, which will then produce code for Konnect entities controllers.

Implementation will be tracked in a separate issue when design is ready.

Acceptance criteria

• A design for spec and code generator for Konnect entities scaffolding and controller code is prepared
• Said design is reviewed and decision whether to accept it and continue with it, is reached