write meta to database

common/cpp/include/common/data_structs.h

common/cpp/include/json_parser/json_parser.h

common/cpp/src/data_structs/data_structs.cpp

common/cpp/src/json_parser/json_parser.cpp

common/cpp/src/json_parser/rapid_json.cpp

common/cpp/src/json_parser/rapid_json.h

common/cpp/unittests/data_structs/test_data_structs.cpp

receiver/src/request.cpp

receiver/src/request_handler_db_write.cpp

receiver/unittests/receiver_mocking.h

receiver/unittests/test_request.cpp

receiver/unittests/test_request_handler_db_writer.cpp