Both packages (mysql-client-5.6 also installs mysql-wsrep-common-5.6) were build from the same source package. That is why mysql-client recommends installing mysql-wsrep-common (check my previous comments for exact links). It is not the job of package management system to correct broken packages, but the job of build team - either to correct broken package, or fix repositories so that our packages are selected in all cases and the situation with mixed packages (upstream and ours) are avoided.
Both packages (mysql-client-5.6 also installs mysql-wsrep- common- 5.6) were build from the same source package. That is why mysql-client recommends installing mysql-wsrep-common (check my previous comments for exact links). It is not the job of package management system to correct broken packages, but the job of build team - either to correct broken package, or fix repositories so that our packages are selected in all cases and the situation with mixed packages (upstream and ours) are avoided.