feat: Added OAuth Support for Public APIs with TokenManager Integration

[sbansla]

Feature

Added OAuth functionality for public APIs.

• We are introducing an OAuth feature where clients can initialize credentials using ClientCredentialProvider and then call an API. The API will be called using a token generated from the client credentials passed via ClientCredentialProvider.
• Token retrieval will occur without client intervention.
• Created a TokenManager service to fetch tokens using the TokenCreator API from the preview-iam domain.
• Updated documentation and examples in the README."

Checklist

• [x] I acknowledge that all my contributions will be made under the project's license
• [ ] I have made a material change to the repo (functionality, testing, spelling, grammar)
• [ ] I have read the Contribution Guidelines and my PR follows them
• [x] I have titled the PR appropriately
• [x] I have updated my branch with the main branch
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added the necessary documentation about the functionality in the appropriate .md file
• [ ] I have added inline documentation to the code I modified

If you have questions, please file a support ticket, or create a GitHub Issue in this repository.

[sonarcloud[bot]]

Quality Gate failed

Failed conditions
44.0% Coverage on New Code (required ≥ 80%)
B Reliability Rating on New Code (required ≥ A)

See analysis details on SonarCloud

Catch issues before they fail your Quality Gate with our IDE extension SonarLint