Add Optional Scopes Param to WindowsProvider GetTokenAsync

[zateutsch]

Fixes #

PR Type

What kind of change does this PR introduce?

Feature

What is the current behavior?

GetTokenAsync always uses scopes set in WindowsProvider constructor.

What is the new behavior?

GetTokenAsync has an optional param to use different scopes for the token request. Behavior remains the same if not provided.

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] Tested code with current supported SDKs
• [x] Contains NO breaking changes

Other information

Documentation for WindowsProvider already shows this arg, so looks like it was intended but never implemented.

[ghost]

Thanks zateutsch for opening a Pull Request! The reviewers will test the PR and highlight if there is any merge conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌

[net-foundation-cla[bot]]

All CLA requirements met.