Add automated release workflow

[frederikprijck]

Changes

This adds the automated release workflow based on what we have in other .NET repositories. The main difference here is that this repository is a mono-repository, publishing multiple packages.

Therefore, our nuget-release workflow and nuget-publish action are different from the other .NET repositories.

Checklist

• [x] I have read the Auth0 general contribution guidelines
• [x] I have read the Auth0 Code of Conduct
• [x] All existing and new tests complete without errors
• [x] All code guidelines in the CONTRIBUTING documentation have been run/followed