feat: added right click entry and shortcut

Author: IacopoSb

src/Resources/Locales/en_US.axaml

@@ -553,6 +553,7 @@
   <x:String x:Key="Text.OpenAppDataDir" xml:space="preserve">Open Data Storage Directory</x:String>
   <x:String x:Key="Text.OpenFile" xml:space="preserve">Open File</x:String>
   <x:String x:Key="Text.OpenInExternalMergeTool" xml:space="preserve">Open in Merge Tool</x:String>
+  <x:String x:Key="Text.OpenInBuiltinMergeTool" xml:space="preserve">Open in Built-in Merge Tool</x:String>
   <x:String x:Key="Text.Optional" xml:space="preserve">Optional.</x:String>
   <x:String x:Key="Text.PageTabBar.New" xml:space="preserve">Create New Tab</x:String>
   <x:String x:Key="Text.PageTabBar.Tab.Bookmark" xml:space="preserve">Bookmark</x:String>

src/Views/WorkingCopy.axaml.cs

@@ -264,6 +264,29 @@ private ContextMenu CreateContextMenuForUnstagedChanges(ViewModels.WorkingCopy v
 
                 if (!change.IsConflicted || change.ConflictReason is Models.ConflictReason.BothAdded or Models.ConflictReason.BothModified)
                 {
+                    if (change.IsConflicted)
+                    {
+                        var isBinary = new Commands.IsBinary(repo.FullPath, "HEAD", change.Path).GetResultAsync().GetAwaiter().GetResult();
+                        if (!isBinary)
+                        {
+                            var openBuiltinMerger = new MenuItem();
+                            openBuiltinMerger.Header = App.Text("OpenInBuiltinMergeTool");
+                            openBuiltinMerger.Icon = App.CreateMenuIcon("Icons.Conflict");
+                            openBuiltinMerger.Tag = OperatingSystem.IsMacOS() ? "⌘+⇧+M" : "Ctrl+Shift+M";
+                            openBuiltinMerger.Click += async (_, e) =>
+                            {
+                                var mergeVm = new ViewModels.MergeConflictEditor(repo, change.Path);
+                                await mergeVm.LoadAsync();
+
+                                var window = TopLevel.GetTopLevel(this) as Window;
+                                var mergeWindow = new MergeConflictEditor { DataContext = mergeVm };
+                                await mergeWindow.ShowDialog(window);
+
+                                e.Handled = true;
+                            };
+                            menu.Items.Add(openBuiltinMerger);
+                        }
+                    }
                     var openMerger = new MenuItem();
                     openMerger.Header = App.Text("OpenInExternalMergeTool");
                     openMerger.Icon = App.CreateMenuIcon("Icons.OpenWith");
@@ -278,6 +301,7 @@ private ContextMenu CreateContextMenuForUnstagedChanges(ViewModels.WorkingCopy v
                         e.Handled = true;
                     };
                     menu.Items.Add(openMerger);
+
                 }
 
                 var explore = new MenuItem();