[go-server] Add go-chi generator to go-server via a router property

[lwj5]

• Added router option to the go-server (mux or chi)
• Updated the mustache files to add go-chi router instead of mux when chi is selected
• Fix missing handlers dependency for mux
• Feature set remains the same
• Added bin/configs/go-server-chi-api-server.yaml to generate go-chi server
• Running with default options bin/configs/go-server-go-api-server.yaml does not change the current generated files! (backwards compatible)

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, 5.1.x, 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.

Hi @antihax @grokify @kemokemo @jirikuncar @ph4r5h4d, please help to take a look at this PR

[wing328]

@lwj5 thanks for the PR. I've tested it locally and didn't spot any issue.