Added more layers to have a vertical slice through Umbraco for CreateMember via backoffice.

Still lots to implement and test, not complete and needs early review.

src/Umbraco.Web.BackOffice/Trees/MemberTreeController.cs

@@ -69,6 +69,7 @@ namespace Umbraco.Web.BackOffice.Trees
             var node = GetSingleTreeNode(id, queryStrings);
 
             //add the tree alias to the node since it is standalone (has no root for which this normally belongs)
+            //TODO: ID is null since new member created
             node.Value.AdditionalData["treeAlias"] = TreeAlias;
             return node;
         }