started with request pool

CMakeLists.txt

...ples/producer/dummy-data-producer/dummy_data_producer.cpp

producer/api/CMakeLists.txt

producer/api/include/producer/producer.h

producer/api/include/producer/producer_error.h

producer/api/src/producer.cpp

producer/api/src/producer_impl.cpp

producer/api/src/producer_impl.h

producer/api/src/request.cpp

producer/api/src/request.h

producer/api/src/request_pool.cpp

producer/api/src/request_pool.h

producer/api/unittests/test_producer.cpp

producer/api/unittests/test_producer_impl.cpp

producer/api/unittests/test_request.cpp

producer/api/unittests/test_request_pool.cpp

receiver/src/statistics.h