add Error class

tests/system_io/read_files_in_folder/CMakeLists.txt

tests/system_io/read_files_in_folder/read_folder_content.cpp

tests/worker/connect_multithread/content_multithread.cpp

tests/worker/curl_http_client_get/curl_httpclient_get.cpp

...orker/next_multithread_broker/next_multithread_broker.cpp

...orker/next_multithread_folder/next_multithread_folder.cpp

worker/api/cpp/CMakeLists.txt

worker/api/cpp/include/worker/data_broker.h

worker/api/cpp/src/broker_helpers.cpp

worker/api/cpp/src/broker_helpers.h

worker/api/cpp/src/curl_http_client.cpp

worker/api/cpp/src/curl_http_client.h

worker/api/cpp/src/data_broker.cpp

worker/api/cpp/src/folder_data_broker.cpp

worker/api/cpp/src/folder_data_broker.h

worker/api/cpp/src/http_client.cpp

worker/api/cpp/src/http_client.h

worker/api/cpp/src/http_error.cpp

worker/api/cpp/src/http_error.h

worker/api/cpp/src/server_data_broker.cpp