Java client, adds responses class + deserializer

[spacether]

Java client, adds responses class + deserializer

• handles case where only status code responses are defined
• handles case where only wildcard code responses are defined
• handles case where both status code and wildcard responses are defined

Notes

Per analysis fo openapi document, these types of responses are used in the wild:

• ResponseType.STATUS_ONLY 29,179
• ResponseType.STATUS_DEFAULT 4,880
• ResponseType.DEFAULT_ONLY 545
• ResponseType.WILDCARD_ONLY 281
• ResponseType.STATUS_WILDCARD 74
• ResponseType.WILDCARD_DEFAULT 21

So it looks like at most two types of responses are combined.. And most used are

1. http status codes only
2. http status codes + default
3. default only

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  mvn clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/python*.
  For Windows users, please run the script in Git BASH.