Additional unit tests for AdvancedCollectionView

[XAML-Knight]

Fixes none, but attempts to address #4339

PR Type

Adding additional unit tests for AdvancedCollectionView

What is the current behavior?

What is the new behavior?

More unit tests for AdvancedCollectionView, to help provide coverage for an issue that was found in a drag and drop scenario (#4339).

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• New component
  • Pull Request has been submitted to the documentation repository instructions. Link:
  • Added description of major feature to project description for NuGet package (4000 total character limit, so don't push entire description over that)
  • If control, added to Visual Studio Design project
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• New major technical changes in the toolkit have or will be added to the Wiki e.g. build changes, source generators, testing infrastructure, sample creation changes, etc...
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes

Other information

See #4339 for more info; to emulate drag and drop, the Year property is modified after removing it from the first ACV, and before adding ("dropping") to the second ACV

[ghost]

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

[XAML-Knight]

Pending the successful approval of related PR #4349 and merge in with main, this PR is to then later be rebased on top of those changes.