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.

windows/.gitignore

@@ -0,0 +1,17 @@
+flutter/ephemeral/
+
+# Visual Studio user-specific files.
+*.suo
+*.user
+*.userosscache
+*.sln.docstates
+
+# Visual Studio build-related files.
+x64/
+x86/
+
+# Visual Studio cache files
+# files ending in .cache can be ignored
+*.[Cc]ache
+# but keep track of directories ending in .cache
+!*.[Cc]ache/