GitHub Actions workflow dispatch for new-client.py

[suztomo]

Let's set up GitHub Actions workflow dispatch for new-client.py invocation, so that the user of the script (a release manager) does not need to prepare the environment (docker, Python version, etc).

• Rename the existing https://github.com/googleapis/google-cloud-java/blob/main/.github/workflows/newclient.yaml to mention it's for testing new client release scripts in a pull request.
• Workflow dispatch can take parameters (document). Design the parameters (very likely the same set of the parameters as new-client.py) The image below is a screenshot from the GitHub documentation, where you can choose parameters when running workflow dispatch:
  
  • What would be required parameters and optional parameters?
• Implement the workflow via a pull request. Your the main branch in your forked repository to test. It's easier to test the pull request in your forked repository (e.g., https://github.com/diegomarquezp/google-cloud-java; You need to enable actions first in a forked repository).
• Try running it with edgenetwork and compare the result (git diff) with feat: [edgenetwork] new module for edgenetwork #10136
• If there's fixes, then create another pull request.