Fix casing of event messages from debug adapter

This change fixes the casing of event messages raised from the debug
adapter.  This issue caused the VS Code debugger UI to not display details
correctly when stopped at a breakpoint.

Author: daviwil

src/PowerShellEditorServices.Protocol/Server/ProtocolServer.cs

@@ -110,20 +110,18 @@ public Task SendEvent<TParams>(
                 this.serverChannel.MessageDispatcher.SynchronizationContext.Post(
                     async (obj) =>
                     {
-                        await this.serverChannel.MessageWriter.WriteMessage(
-                            Message.Event(
-                                eventType.MethodName,
-                                JToken.FromObject(eventParams)));
+                        await this.serverChannel.MessageWriter.WriteEvent(
+                            eventType,
+                            eventParams);
                     }, null);
 
                 return Task.FromResult(true);
             }
             else
             {
-                return this.serverChannel.MessageWriter.WriteMessage(
-                    Message.Event(
-                        eventType.MethodName,
-                        JToken.FromObject(eventParams)));
+                return this.serverChannel.MessageWriter.WriteEvent(
+                    eventType,
+                    eventParams);
             }
         }