Merge branch 'f-files' into 'dev'

CMakeLists.txt

README_SETUP.md

conanfile.py

doc/capi/index.rst.in

include/CMakeLists.txt

include/caosdb/connection.h

include/caosdb/entity.h

include/caosdb/file_transmission/download_request_handler.h

include/caosdb/file_transmission/file_error.h

include/caosdb/file_transmission/file_reader.h

include/caosdb/file_transmission/file_writer.h

...e/caosdb/file_transmission/register_file_upload_handler.h

include/caosdb/file_transmission/upload_request_handler.h

include/caosdb/handler_interface.h

include/caosdb/protobuf_helper.h

include/caosdb/status_code.h

include/caosdb/transaction.h

include/caosdb/transaction_handler.h

include/caosdb/transaction_status.h

include/caosdb/unary_rpc_handler.h