Added cancel sessions with no user plugin to the default plugins

This makes sure that no matter what, you have to specify a user when
submitting a session event. The console app was submitting a session
start but this sessions plugin wasn't registered yet, so empty sessions
continued to be sent.

Author: niemyjski

Source/Shared/Extensions/ExceptionlessConfigurationExtensions.cs

@@ -88,8 +88,6 @@ public static string GetInstallId(this ExceptionlessConfiguration config) {
         }
 
         public static void UseSessions(this ExceptionlessConfiguration config, bool sendHeartbeats = true) {
-            config.AddPlugin<CancelSessionsWithNoUserPlugin>();
-
             if (sendHeartbeats)
                 config.AddPlugin<HeartbeatPlugin>();
         }

Source/Shared/Plugins/EventPluginManager.cs

@@ -29,6 +29,7 @@ public static void AddDefaultPlugins(ExceptionlessConfiguration config) {
             config.AddPlugin<DuplicateCheckerPlugin>();
             config.AddPlugin<EnvironmentInfoPlugin>();
             config.AddPlugin<SubmissionMethodPlugin>();
+            config.AddPlugin<CancelSessionsWithNoUserPlugin>();
         }
     }
 }