Added CenterHorizontally and CenterVertically to the ListView Extensions | Smooth Scroll Into View

[HotCakeX]

Added CenterHorizontally and CenterVertically for the ListView Extensions, Smooth Scrolling Into View

Fixes

Fixes this issue: https://github.com/CommunityToolkit/Windows/issues/647

PR Type

• Bugfix

What is the current behavior?

Smooth Scroll Into View has a Center behavior that centers the ListView both horizontally and vertically at the same time.

What is the new behavior?

The 2 new behaviors allow for only centering horizontally or only centering vertically.

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• [x] Based off latest main branch of toolkit
• [x] Tested code with current supported SDKs
• [ ] New component
  • [ ] Documentation has been added
  • [ ] Sample in sample app has been added
  • [x] Analyzers are passing for documentation and samples
  • [ ] Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• [x] Tests for the changes have been added (if applicable)
• [ ] Header has been added to all new source files
• [x] Contains NO breaking changes

Other information

Talked about this with @michael-hawker on Discord

[michael-hawker]

Thanks @HotCakeX, marking this as a draft for now. I think we should breakdown the changes/uses of the new scenario on the API surface a bit more. Let's chat in the issue more.