Fixes: Regression in ColorPicker ColorPalette

[Marv51]

Fixes

Fixes #833

Fixes regession, where PaletteItemGridView would not be updated when the selected color changed.

PR Type

What kind of change does this PR introduce?

Bugfix

What is the current behavior?

See issue, the selection state of the GridView does not stay synchronized with the other color picker components.

What is the new behavior?

This restores the spirit of the previous TwoWay data binding between the SelectedValue of the GridView and the selected color.

PR Checklist

Please check if your PR fulfills the following requirements:

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit
• Tested code with current supported SDKs (I tested the Wasdk and Wasm sample projects and created an automated test, not sure how and if I should test anything else)
• New component
  • Documentation has been added
  • Sample in sample app has been added
  • Analyzers are passing for documentation and samples
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• Tests for the changes have been added (if applicable)
• Header has been added to all new source files
• Contains NO breaking changes (Previous behavior was clearly broken, so I would not consider it breaking in any way)

Other information

I tested this with the "ColorPicker.Wasdk" and "ColorPicker.Wasm" sample app manually, both previously repro'd the bug and every thing works well with this fix included.

I also create a test case for this issue in the automated tests for colorpicker.