Moved EditorInfoBarService to its own folder, export as workspace service

src/EditorFeatures/Core/Implementation/Workspaces/EditorInfoBarService.cs → src/EditorFeatures/Core/Implementation/InfoBar/EditorInfoBarService.cs

-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
 using Microsoft.CodeAnalysis.Extensions;
+using Microsoft.CodeAnalysis.Host.Mef;
 using Microsoft.CodeAnalysis.Internal.Log;
 
 namespace Microsoft.CodeAnalysis.Editor.Implementation.Workspaces
 {
+    [ExportWorkspaceService(typeof(IInfoBarService))]
     internal class EditorInfoBarService : IInfoBarService
     {
         public void ShowInfoBarInActiveView(string message, params InfoBarUI[] items)