U4-4761: adds overload to treeattribute

src/Umbraco.Web/Trees/TreeAttribute.cs

@@ -8,6 +8,16 @@ namespace Umbraco.Web.Trees
     [AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
     public class TreeAttribute : Attribute
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="TreeAttribute"/> class.
+        /// </summary>
+        /// <param name="appAlias">The app alias.</param>
+        /// <param name="alias">The alias.</param>
+        public TreeAttribute(string appAlias,
+            string alias) : this(appAlias, alias, null)
+        {
+        }
+
         /// <summary>
         /// Initializes a new instance of the <see cref="TreeAttribute"/> class.
         /// </summary>
@@ -20,7 +30,7 @@ namespace Umbraco.Web.Trees
         /// <param name="sortOrder">The sort order.</param>
         public TreeAttribute(string appAlias,
             string alias,
-            string title = "",
+            string title,
             string iconClosed = "icon-folder",
             string iconOpen = "icon-folder-open",
             bool initialize = true,
@@ -35,6 +45,8 @@ namespace Umbraco.Web.Trees
             SortOrder = sortOrder;
         }
 
+
+
         public string ApplicationAlias { get; private set; }
         public string Alias { get; private set; }
         public string Title { get; private set; }