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/Tests/Microsoft.CmdPal.Common.UnitTests/Text/StringFolderTests.cs

@@ -0,0 +1,55 @@
+// 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.Common.Text;
+
+namespace Microsoft.CmdPal.Common.UnitTests.Text;
+
+[TestClass]
+public class StringFolderTests
+{
+    private readonly StringFolder _folder = new();
+
+    [TestMethod]
+    [DataRow(null, "")]
+    [DataRow("", "")]
+    [DataRow("abc", "ABC")]
+    [DataRow("ABC", "ABC")]
+    [DataRow("a\\b", "A/B")]
+    [DataRow("a/b", "A/B")]
+    [DataRow("ÁBC", "ABC")] // Diacritic removal
+    [DataRow("ñ", "N")]
+    [DataRow("hello world", "HELLO WORLD")]
+    public void Fold_RemoveDiacritics_Works(string input, string expected)
+    {
+        Assert.AreEqual(expected, _folder.Fold(input, removeDiacritics: true));
+    }
+
+    [TestMethod]
+    [DataRow("abc", "ABC")]
+    [DataRow("ÁBC", "ÁBC")] // No diacritic removal
+    [DataRow("a\\b", "A/B")]
+    public void Fold_KeepDiacritics_Works(string input, string expected)
+    {
+        Assert.AreEqual(expected, _folder.Fold(input, removeDiacritics: false));
+    }
+
+    [TestMethod]
+    public void Fold_IsAlreadyFolded_ReturnsSameInstance()
+    {
+        var input = "ALREADY/FOLDED";
+        var result = _folder.Fold(input, removeDiacritics: true);
+        Assert.AreSame(input, result);
+    }
+
+    [TestMethod]
+    public void Fold_WithNonAsciiButNoDiacritics_ReturnsFolded()
+    {
+        // E.g. Cyrillic or other scripts that might not decompose in a simple way or just upper case
+        // "привет" -> "ПРИВЕТ"
+        var input = "привет";
+        var expected = "ПРИВЕТ";
+        Assert.AreEqual(expected, _folder.Fold(input, removeDiacritics: true));
+    }
+}