Add Windows runner files for high DPI support and console output

- Created runner.exe.manifest to enable DPI awareness and dark mode support.
- Implemented utility functions in utils.cpp and utils.h for console creation and command line argument handling.
- Developed Win32Window class in win32_window.cpp and win32_window.h to manage high DPI-aware windows, including theme updates and message handling.

windows/runner/utils.h

@@ -0,0 +1,19 @@
+#ifndef RUNNER_UTILS_H_
+#define RUNNER_UTILS_H_
+
+#include <string>
+#include <vector>
+
+// Creates a console for the process, and redirects stdout and stderr to
+// it for both the runner and the Flutter library.
+void CreateAndAttachConsole();
+
+// Takes a null-terminated wchar_t* encoded in UTF-16 and returns a std::string
+// encoded in UTF-8. Returns an empty std::string on failure.
+std::string Utf8FromUtf16(const wchar_t* utf16_string);
+
+// Gets the command line arguments passed in as a std::vector<std::string>,
+// encoded in UTF-8. Returns an empty std::vector<std::string> on failure.
+std::vector<std::string> GetCommandLineArguments();
+
+#endif  // RUNNER_UTILS_H_