let's always disconnect a user connection before dropping the said user.
MariaDB is traditionally very tolerant to active connections
of the dropped user, which isn't the case for most other databases.
Let's avoid unintentionally spreading incompatible behavior
and disconnect before drop.
Except in cases when the test specifically tests such a behavior.
This is a 10.3 specific part of MDEV-13049.
It disables automatic sorting for
"SELECT .. FROM INFORMATION_SCHEMA.{SCHEMATA|TABLES}"
and adjusts the affected tests accordingly.
The problem lies in not checking role privileges as well during SHOW
DATABASES command. This problem is also apparent for SHOW CREATE
DATABASE command.
Other SHOW COMMANDS make use of check_access, which in turn makes use of
acl_get for both priv_user and priv_role parts, which allows them to
function correctly.
