test: move fuzzing tests from google/oss-fuzz repository (#4719)

JSON/fuzzing/JsonParse.cpp

@@ -0,0 +1,26 @@
+#include "Poco/JSON/Parser.h"
+
+using namespace Poco;
+using namespace Poco::JSON;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+{
+	std::string json(reinterpret_cast<const char*>(data), size);
+	Parser parser;
+	Dynamic::Var result;
+
+	try
+	{
+		result = parser.parse(json);
+	}
+	catch (Exception& e)
+	{
+		return 0;
+	}
+	catch (const std::exception& e)
+	{
+		return 0;
+	}
+
+	return 0;
+}