gets surface controllers and front-end api controllers auto-routed, adds tests

src/Umbraco.Web.Common/Controllers/UmbracoApiController.cs

@@ -1,4 +1,4 @@
-using Umbraco.Core.Composing;
+using Umbraco.Core.Composing;
 
 namespace Umbraco.Web.Common.Controllers
 {
@@ -7,8 +7,9 @@ namespace Umbraco.Web.Common.Controllers
     /// </summary>
     public abstract class UmbracoApiController : UmbracoApiControllerBase, IDiscoverable
     {
-        // TODO: Should this only exist in the back office project? These really are only ever used for the back office AFAIK
-
+        /// <summary>
+        /// Initializes a new instance of the <see cref="UmbracoApiController"/> class.
+        /// </summary>
         protected UmbracoApiController()
         {
         }