fix(connection): use parameter in context menu command handlers

OnConnect, OnDisconnect, and OnEditConnection were only checking
SelectedNode but not the command parameter, causing context menu
commands to fail when the right-clicked node wasn't already selected.

Author: CalvinAllen

src/CodingWithCalvin.CouchbaseExplorer/ViewModels/CouchbaseExplorerViewModel.cs

@@ -179,7 +179,8 @@ private void CollapseNode(TreeNodeBase node)
 
         private async void OnConnect(object parameter)
         {
-            if (SelectedNode is ConnectionNode connection)
+            var connection = parameter as ConnectionNode ?? SelectedNode as ConnectionNode;
+            if (connection != null)
             {
                 await ConnectToNodeAsync(connection);
             }
@@ -241,7 +242,8 @@ private bool CanConnect(object parameter)
 
         private async void OnDisconnect(object parameter)
         {
-            if (SelectedNode is ConnectionNode connection)
+            var connection = parameter as ConnectionNode ?? SelectedNode as ConnectionNode;
+            if (connection != null)
             {
                 try
                 {
@@ -306,7 +308,8 @@ private async Task LoadBucketsAsync(ConnectionNode connection)
 
         private void OnEditConnection(object parameter)
         {
-            if (SelectedNode is ConnectionNode connection)
+            var connection = parameter as ConnectionNode ?? SelectedNode as ConnectionNode;
+            if (connection != null)
             {
                 var existingNames = GetExistingConnectionNames();
                 var dialogViewModel = new ConnectionDialogViewModel(existingNames, connection);