more work on config

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/json_parser/test_json_parser.cpp

receiver/CMakeLists.txt

receiver/src/receiver_config.cpp

receiver/unittests/test_config.cpp

...matic/json_parser/parse_config_file/parse_config_file.cpp