[OpenAPI Generator] Enable allow-list for API and Model classes

[newtork]

Please find similar setting names in the original OpenAPI generator.

Usage:

• In additionalProperties define modelsToGenerate and apisToGenerate. Use <space> or , as delimiter.

<plugin>
  <groupId>com.sap.cloud.sdk.datamodel</groupId>
  <artifactId>openapi-generator-maven-plugin</artifactId>
  <configuration>
    <additionalProperties>
      <apisToGenerate>Sodas,Orders</apisToGenerate>
      <modelsToGenerate>
        Order
        OrderWithTimestamp
        Soda
        SodaWithId
      </modelsToGenerate>
    </additionalProperties>

Note:

• To enable the generation of file SodasApi.java, the apisToGenerate field should contain Sodas (without suffix),
• If apisToGenerate is not defined, all APIs are allowed. Same with modelsToGenerate.

Definition of Done

• Functionality scope stated & covered
• Tests cover the scope above
• Error handling created / updated & covered by the tests above
• Documentation updated
• Release notes updated

[newtork]

Moved stale PR to personal fork.

[MatKuhr]

generally lgtm. However, allow-list is not ideal for our purposes. E.g. for orchestration we already have 47 files, and typically we would want to only exclude a few files from generation.

Did you check the options for block-list? Maybe using .openapi-generator-ignore can be made to work?

[MatKuhr]

(minor) since there is only one API, this only tests that NotExist doesn't cause the generation to fail..

[newtork]

I don't understand the implication of this statement

[newtork]

After realizing the allow/block-listing of model classes leads to non-compileable code, I'm hesitant to introduce this feature. I feel like we need to go back to the drawing board.