Implement Inventory Methods; Add static Inventory object to static Program class

C968Project/Views/MainScreen.cs

@@ -5,5 +5,8 @@ public partial class MainScreen : Form
     public MainScreen()
     {
         InitializeComponent();
+
+        productsDataGridView.DataSource = Program.Inventory.Products;
+        partsDataGridView.DataSource = Program.Inventory.Parts;
     }
 }