WIP: fix circular includes

CMakeLists.txt

include/CMakeLists.txt

include/caosdb/authentication.h

include/caosdb/certificate_provider.h

include/caosdb/configuration.h

include/caosdb/connection.h

include/caosdb/entity.h

include/caosdb/info.h

include/caosdb/transaction.h

include/caosdb/utility.h

src/caosdb/authentication.cpp

src/caosdb/configuration.cpp

src/caosdb/connection.cpp

src/caosdb/transaction.cpp

src/ccaosdb.cpp

src/ccaosdbcli.c

src/cxxcaosdbcli.cpp

test/test_ccaosdb.cpp

test/test_configuration.cpp

test/test_connection.cpp