Update templates to use ApplicationConfiguration.Initialize() (#5529)

Relates to #5035
Relates to #5071

Author: RussKie

pkg/Microsoft.Dotnet.WinForms.ProjectTemplates/content/WinFormsApplication-CSharp/.template.config/template.json

@@ -53,6 +53,10 @@
       "type": "computed",
       "value": "(Framework == \"netcoreapp3.1\")"
     },
+    "UseApplicationBoilerplate": {
+      "type": "computed",
+      "value": "(Framework == \"net5.0\")"
+    },
     "langVersion": {
       "type": "parameter",
       "datatype": "text",
@@ -94,16 +98,29 @@
         {
           "condition": "(UseWindowsDesktopSdk)",
           "exclude": [
-            "Company.WinFormsApplication1.csproj"
+            "Company.WinFormsApplication1.csproj",
+            "Program.cs"
+          ],
+          "rename": {
+            "Company.WinFormsApplication3x1.csproj": "Company.WinFormsApplication1.csproj",
+            "Program.boilerplate.cs": "Program.cs"
+          }
+        },
+        {
+          "condition": "(!UseWindowsDesktopSdk && UseApplicationBoilerplate)",
+          "exclude": [
+            "Company.WinFormsApplication3x1.csproj",
+            "Program.cs"
           ],
           "rename": {
-            "Company.WinFormsApplication3x1.csproj": "Company.WinFormsApplication1.csproj"
+            "Program.boilerplate.cs": "Program.cs"
           }
         },
         {
-          "condition": "(!UseWindowsDesktopSdk)",
+          "condition": "(!UseWindowsDesktopSdk && !UseApplicationBoilerplate)",
           "exclude": [
-            "Company.WinFormsApplication3x1.csproj"
+            "Company.WinFormsApplication3x1.csproj",
+            "Program.boilerplate.cs"
           ]
         }
       ]

pkg/Microsoft.Dotnet.WinForms.ProjectTemplates/content/WinFormsApplication-CSharp/Program.boilerplate.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace Company.WinFormsApplication1
+{
+    static class Program
+    {
+        /// <summary>
+        ///  The main entry point for the application.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            Application.SetHighDpiMode(HighDpiMode.SystemAware);
+            Application.EnableVisualStyles();
+            Application.SetCompatibleTextRenderingDefault(false);
+            Application.Run(new Form1());
+        }
+    }
+}

pkg/Microsoft.Dotnet.WinForms.ProjectTemplates/content/WinFormsApplication-CSharp/Program.cs

@@ -14,9 +14,7 @@ static class Program
         [STAThread]
         static void Main()
         {
-            Application.SetHighDpiMode(HighDpiMode.SystemAware);
-            Application.EnableVisualStyles();
-            Application.SetCompatibleTextRenderingDefault(false);
+            ApplicationConfiguration.Initialize();
             Application.Run(new Form1());
         }
     }