ExecuteGoToSolutionOrPullRequestFileCommand metric

Add metric for number of times
ExecuteGoToSolutionOrPullRequestFileCommand is executed.

Author: jcansdale

src/GitHub.Exports/Models/UsageModel.cs

@@ -75,6 +75,7 @@ public class MeasuresModel
             public int NumberOfOriginsUpdatedWhenForkingRepo { get; set; }
             public int NumberOfUpstreamsAddedWhenForkingRepo { get; set; }
             public int NumberOfTrackMasterUpstreamWhenForkingRepo { get; set; }
+            public int ExecuteGoToSolutionOrPullRequestFileCommand { get; set; }
             public int NumberOfNavigateToPullRequestFileDiff { get; set; }
             public int NumberOfNavigateToCodeView { get; set; }
             public int ExecuteToggleInlineCommentMarginCommand { get; set; }

src/GitHub.VisualStudio/Commands/GoToSolutionOrPullRequestFileCommand.cs

@@ -1,6 +1,7 @@
 using System;
 using System.ComponentModel.Composition;
 using GitHub.Services;
+using GitHub.Extensions;
 using GitHub.VisualStudio;
 using GitHub.Services.Vssdk.Commands;
 using Microsoft.VisualStudio;
@@ -54,6 +55,8 @@ public GoToSolutionOrPullRequestFileCommand(
 
         public override async Task Execute()
         {
+            usageTracker.Value.IncrementCounter(x => x.ExecuteGoToSolutionOrPullRequestFileCommand).Forget();
+
             try
             {
                 var sourceView = pullRequestEditorService.Value.FindActiveView();