[UX] New dashboard & refactored KeyVisual (#40214)

### 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.
<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

Closes #39520
Closes #32944

---------

Co-authored-by: Jay <65828559+Jay-o-Way@users.noreply.github.com>
Co-authored-by: Jaylyn Barbee <51131738+Jaylyn-Barbee@users.noreply.github.com>

src/settings-ui/Settings.UI/ViewModels/DashboardModuleItem.cs

@@ -36,23 +36,9 @@ namespace Microsoft.PowerToys.Settings.UI.ViewModels
         public List<object> Shortcut { get; set; }
     }
 
-    public partial class DashboardModuleKBMItem : DashboardModuleItem
+    public partial class DashboardModuleActivationItem : DashboardModuleItem
     {
-        private List<KeysDataModel> _remapKeys = new List<KeysDataModel>();
-
-        public List<KeysDataModel> RemapKeys
-        {
-            get => _remapKeys;
-            set => _remapKeys = value;
-        }
-
-        private List<AppSpecificKeysDataModel> _remapShortcuts = new List<AppSpecificKeysDataModel>();
-
-        public List<AppSpecificKeysDataModel> RemapShortcuts
-        {
-            get => _remapShortcuts;
-            set => _remapShortcuts = value;
-        }
+        public string Activation { get; set; }
     }
 
     public partial class DashboardModuleItem : INotifyPropertyChanged