feat: Implement Windows runner for Flutter application

- Added FlutterWindow class to manage the Flutter view within a Win32 window.
- Created main entry point in main.cpp to initialize and run the Flutter application.
- Implemented utility functions for console attachment and command line argument parsing.
- Added resource management for application icon and manifest.
- Enhanced Win32Window class for DPI awareness and theme management.
- Included necessary headers and resource files for building the Windows runner.

AppIcon.icon/icon.json

@@ -0,0 +1,38 @@
+{
+  "fill" : {
+    "automatic-gradient" : "extended-srgb:0.00000,0.53333,1.00000,1.00000"
+  },
+  "groups" : [
+    {
+      "layers" : [
+        {
+          "blend-mode" : "soft-light",
+          "glass" : true,
+          "image-name" : "icon.png",
+          "name" : "icon",
+          "position" : {
+            "scale" : 1.4,
+            "translation-in-points" : [
+              2.625,
+              5.3203125
+            ]
+          }
+        }
+      ],
+      "shadow" : {
+        "kind" : "neutral",
+        "opacity" : 0.5
+      },
+      "translucency" : {
+        "enabled" : true,
+        "value" : 0.5
+      }
+    }
+  ],
+  "supported-platforms" : {
+    "circles" : [
+      "watchOS"
+    ],
+    "squares" : "shared"
+  }
+}