Add Service Principal parameters for authentication

[Jojobit]

Enhanced the Connect-FabricAccount function by adding support for Service Principal authentication. This includes new parameters for ServicePrincipalId, ServicePrincipalSecret, and Credential, allowing for more flexible authentication options. Updated the unit tests to reflect these changes and ensure proper validation.

Thank you!

Pull Request

Added

• support for SP autnetication [closes Authentication needs to support ServicePrincipal #61]

Task list

• The PR represents a single logical change. i.e. Cosmetic updates should go in different PRs.
• Added an entry under the Unreleased section of in the CHANGELOG.md as per format.
• Local clean build passes without issue or fail tests (build.ps1 -ResolveDependency).
• Resource documentation added/updated in README.md.
• Resource parameter descriptions added/updated in README.md, schema.mof
  and comment-based help.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated. See DSC Resource Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

[github-actions]

Linux Test Results

4 617 tests   4 616 ✅  43s ⏱️
  410 suites      1 💤
    1 files        0 ❌

Results for commit bdc0836.

♻️ This comment has been updated with latest results.

[github-actions]

WinPS51 Test Results

4 617 tests   4 616 ✅  55s ⏱️
  410 suites      1 💤
    1 files        0 ❌

Results for commit bdc0836.

♻️ This comment has been updated with latest results.

[github-actions]

WinPS71 Test Results

4 617 tests   4 616 ✅  51s ⏱️
  410 suites      1 💤
    1 files        0 ❌

Results for commit bdc0836.

♻️ This comment has been updated with latest results.

[Jojobit]

@jpomfret @SQLDBAWithABeard can you help me with a PR approval?

[jpomfret]

@Jojobit - yeah!! Nice add 🙂 - added a couple of comments, where possible I made suggestions so should make it easy for you to add them in if you're happy

[SQLDBAWithABeard]

Happy to make the changes for you @Jojobit - If you would like.

Thank you, this is awesome, so good to see all of your hard work coming to fruition here and thank you for creating the first PR of the next round !!

[Jojobit]

@jpomfret @SQLDBAWithABeard feel free