Added SearchType enum

Author: Sergio0694

Microsoft.Toolkit.Uwp.UI/Enums/SearchType.cs

@@ -0,0 +1,24 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace Microsoft.Toolkit.Uwp.UI
+{
+    /// <summary>
+    /// Indicates a type of search for elements in a visual or logical tree.
+    /// </summary>
+    public enum SearchType
+    {
+        /// <summary>
+        /// Depth-first search, where each branch is recursively explored until the end before moving to the next one.
+        /// </summary>
+        DepthFirst,
+
+        /// <summary>
+        /// Breadth-first search, where each depthwise level is completely explored before moving to the next one.
+        /// This is particularly useful if the target element to find is known to not be too distant from the starting
+        /// point and the whole visual/logical tree from the root is large enough, as it can reduce the traversal time.
+        /// </summary>
+        BreadthFirst
+    }
+}