Currently, only data return types of String and File are supported, this PR allows for a Binary return type, which returns the raw binary data from a gotten file. This data can be written to a file, allowing users to have the option to receive raw binary data without needed to download a temporary file. This can be validated by setting debug_return_type to 'Binary' when making a get request, and then writing the data received to a file.

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:

  ./mvnw 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/java*.
  For Windows users, please run the script in Git BASH.
• File the PR against the correct branch: master (5.3.0), 6.0.x
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

@cliffano (2017/07) @zlx (2017/09) @autopp (2019/02)