[UX] New dashboard & refactored KeyVisual

[niels9001]

Summary of the Pull Request

TO DO: latest design specs for KeyVisual

New dashboard UX

Dashboard.mp4

Update available:

No update available:

Updated KeyVisual and Shortcut control

• Refactoring KeyVisual to remove redundant properties and UI elements, and using Styles for better customization.
• Shortcut control now shows a "Configure shortcut" label when there's no shortcut configured.
  

Other changes

• Consolidated converters that were used across pages in App.xaml.cs with consistent naming.
• Renamed templated controls (from .cs to .xaml.cs) and moving those to the Controls root folder vs. individual folders for a better overview.

PR Checklist

• Closes: Dashboard/Feature overview #39520
• Communication: I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end-user-facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed