change to reflect 1.0.18's current signature, add missing usings

Author: Jasmine

src/GitHub.VisualStudio/Base/MenuBase.cs

@@ -7,6 +7,9 @@
 using GitHub.Api;
 using NullGuard;
 using GitHub.UI;
+using System.Diagnostics;
+using System.Linq;
+using GitHub.Primitives;
 
 namespace GitHub.VisualStudio
 {

src/GitHub.VisualStudio/Menus/CopyLink.cs

@@ -23,7 +23,7 @@ public CopyLink([Import(typeof(SVsServiceProvider))] IServiceProvider servicePro
         public Guid Guid => GuidList.guidContextMenuSet;
         public int CmdId => PkgCmdIDList.copyLinkCommand;
 
-        public async void Activate([AllowNull]object data = null)
+        public async void Activate()
         {
             var isgithub = await IsGitHubRepo();
             if (!isgithub)

src/GitHub.VisualStudio/Menus/OpenLink.cs

@@ -21,7 +21,7 @@ public OpenLink([Import(typeof(SVsServiceProvider))] IServiceProvider servicePro
         public Guid Guid => GuidList.guidContextMenuSet;
         public int CmdId => PkgCmdIDList.openLinkCommand;
 
-        public async void Activate([AllowNull]object data = null)
+        public async void Activate()
         {
             var isgithub = await IsGitHubRepo();
             if (!isgithub)