Refactor: extract interfaces (#484)

* .

* MatchDetail

* rm

* resp

* log

* f

src/WireMock.Net/IMapping.cs

@@ -99,7 +99,7 @@ namespace WireMock
         /// </summary>
         /// <param name="requestMessage">The request message.</param>
         /// <param name="nextState">The Next State.</param>
-        /// <returns>The <see cref="RequestMatchResult"/>.</returns>
+        /// <returns>The <see cref="IRequestMatchResult"/>.</returns>
         RequestMatchResult GetRequestMatchResult(RequestMessage requestMessage, [CanBeNull] string nextState);
     }
 }