Improve the generation of the OpenAPI specification from JSON schema

1. Make improvements to the generator in https://github.com/plantbreeding/brapi-schema-tools
2. Release snapshot
3. Create a branch associated with this issue in https://github.com/plantbreeding/BrAPI
4. Update the snapshot version in variable brapiSchemaToolsVersion in https://github.com/plantbreeding/BrAPI/blob/brapi-V2.1/generator/build.gradle
5. Wait for CI
6. pull the generated code
7. look at the generated comparison markdown
8. If there are unacceptable differences, repeat the steps above
9. Merge branch to main branch if acceptable.

[guydavenport]

I am the ghost :)