feat: add windows function helper

- add windows function helper namespace for some commonly used windows functions.
- add corresponding testbench for added code.

src/WinFctHelper.cpp

@@ -0,0 +1,78 @@
+#include "WinFctHelper.hpp"
+#if YYCC_OS == YYCC_OS_WINDOWS
+
+#include "EncodingHelper.hpp"
+
+namespace YYCC::WinFctHelper {
+	
+	HMODULE GetCurrentModule() {
+		// Reference: https://stackoverflow.com/questions/557081/how-do-i-get-the-hmodule-for-the-currently-executing-code
+		HMODULE hModule = NULL;
+		GetModuleHandleExW(
+			GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,	// get address and do not inc ref counter.
+			(LPCWSTR)GetCurrentModule,
+			&hModule);
+
+		return hModule;
+	}
+
+	std::string GetTempDirectory() {
+		// create wchar buffer for receiving the temp path.
+		std::wstring wpath(MAX_PATH + 1u, L'\0');
+		DWORD expected_size;
+
+		// fetch temp folder
+		while (true) {
+			if ((expected_size = GetTempPathW(static_cast<DWORD>(wpath.size()), wpath.data())) == 0) {
+				// failed, set to empty
+				expected_size = 0;
+				// and break while
+				break;
+			}
+
+			if (expected_size > static_cast<DWORD>(wpath.size())) {
+				// buffer is too short, need enlarge and do fetching again
+				wpath.resize(expected_size);
+			} else {
+				// ok. shrink to real length,  break while
+				break;
+			}
+		}
+
+		// resize result
+		wpath.resize(expected_size);
+		// convert to utf8 and return
+		return YYCC::EncodingHelper::WcharToUTF8(wpath.c_str());
+	}
+
+	std::string GetModuleName(HINSTANCE hModule) {
+		// create wchar buffer for receiving the temp path.
+		std::wstring wpath(MAX_PATH + 1u, L'\0');
+		DWORD copied_size;
+
+		while (true) {
+			if ((copied_size = GetModuleFileNameW(hModule, wpath.data(), static_cast<DWORD>(wpath.size()))) == 0) {
+				// failed, return empty string
+				copied_size = 0;
+				break;
+			}
+
+			// check insufficient buffer
+			if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+				// buffer is not enough, enlarge it and try again.
+				wpath.resize(wpath.size() + MAX_PATH);
+			} else {
+				// ok, break while
+				break;
+			}
+		}
+		
+		// resize result
+		wpath.resize(copied_size);
+		// convert to utf8 and return
+		return YYCC::EncodingHelper::WcharToUTF8(wpath.c_str());
+	}
+
+}
+
+#endif