Improve the shader UID debugging stuff and merge it to VideoCommon, effectively enabling it in D3D9 and D3D11 as well.

Source/Core/Common/Src/MsgHandler.cpp

@@ -53,7 +53,7 @@ bool MsgAlert(bool yes_no, int Style, const char* format, ...)
 {
 	// Read message and write it to the log
 	std::string caption;
-	char buffer[4096];
+	char buffer[2048];
 
 	static std::string info_caption;
 	static std::string warn_caption;