CmdPal: Removing Core projects (#45693)

Functionally, no differences.

- Removed Core projects.
- Core.Common => Microsoft.CmdPal.Common
- Core.ViewModels => Microsoft.CmdPal.UI.ViewModels

---------

Co-authored-by: Jiří Polášek <me@jiripolasek.com>

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/DetailsElementViewModel.cs

@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.CmdPal.UI.ViewModels.Models;
+using Microsoft.CommandPalette.Extensions;
+
+namespace Microsoft.CmdPal.UI.ViewModels;
+
+public abstract partial class DetailsElementViewModel(IDetailsElement _detailsElement, WeakReference<IPageContext> context) : ExtensionObjectViewModel(context)
+{
+    private readonly ExtensionObject<IDetailsElement> _model = new(_detailsElement);
+
+    public string Key { get; private set; } = string.Empty;
+
+    public override void InitializeProperties()
+    {
+        var model = _model.Unsafe;
+        if (model is null)
+        {
+            return;
+        }
+
+        Key = model.Key ?? string.Empty;
+        UpdateProperty(nameof(Key));
+    }
+}