AutoSuggestBox refactoring

[IvanDmitriev1]

Implements a AutoSuggestBox control almost like in winui 3.
Closes: #454, #489, #281, #353

Pull request type

• Update
• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes

What is the current behavior?

• You cannot navigate to the suggested elements using the keyboard.

What is the new behavior?

• You can navigate to the suggested elements using the keyboard.
• Popup will close if AutoSuggestBox lost focus.

[pomianowski]

Hi, thanks for trying to improve the AutoSuggestBox. Apart from changing the view model convention for the page and namespaces, everything looks neat. Thanks for your contribution.

[pomianowski]

Or not, sometimes when I type only one letter, the pop up doesn't show up.

Steps to reproduce

• Open Gallery app in Debug | Any CPU configuration
• Type a in the AutoSuggestBox of the main NavigationView
• Click the clear button of the AutoSuggestBox
• Type a in the AutoSuggestBox of the main NavigationView, again
• The popup with suggestions does not show up