refactor: move COM type and guard into independent file

- move COM types and guard into independent file and namespace COMHelper because not only dialog, but also other parts also need to use COM related fucntion.
- remove ParserHelper.cpp because it is empty (ParserHelper is header only namespace).
- Add a function fetching LOCALAPPDATA in WinFctHelper.

src/COMHelper.cpp

@@ -0,0 +1,40 @@
+#include "COMHelper.hpp"
+#if YYCC_OS == YYCC_OS_WINDOWS
+
+namespace YYCC::COMHelper {
+
+	/**
+	 * @brief The guard for initialize COM environment.
+	 * @details This class will try initializing COM environment by calling CoInitialize when constructing,
+	 * and it also will try uninitializing COM environment when destructing.
+	 * If initialization failed, uninitialization will not be executed.
+	*/
+	class ComGuard {
+	public:
+		ComGuard() : m_HasInit(false) {
+			HRESULT hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
+			if (SUCCEEDED(hr)) m_HasInit = true;
+		}
+		~ComGuard() {
+			if (m_HasInit) {
+				CoUninitialize();
+			}
+		}
+
+	protected:
+		bool m_HasInit;
+	};
+
+	/**
+	 * @brief The instance of COM environment guard.
+	 * @details Dialog related function need COM environment,
+	 * so we need initializing COM environment when loading this module,
+	 * and uninitializing COM environment when we no longer use this module.
+	 * So we use a static instance in here.
+	 * And make it be const so no one can change it.
+	*/
+	static const ComGuard c_ComGuard;
+
+}
+
+#endif