Java, adds tag apis

[spacether]

Java, adds tag apis

• operation class now includes a path prefix to prevent collisions
• java tooling layer: deprecates getSchemaPascalCaseName
• many java classes updated to include PathVerb prefix so one can use multiple api client methods in the same call site
  • requestBody
  • responses class
  • Query/Header/Path/CookieParameters schema classes
  • individual response classes
• operation docs describe the operationId interface
• adds path api docs
• adds tag api docs
• readme sections re-organized to use the same order that the python generator uses
• endpoint links to all apiclient methods that are available to call endpoints

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/generate_samples_configs/python*
  For Windows users, please run the script in Git BASH.