C-z is extermelly useful for some users (like myself), so provide a way
to configure it in client and avoid it's ignorance in clickhouse-disks
(I hope it is OK since it is not that known utility and it does not have
it's own configuration, while cli option is useless, one should remeber
about it).
Honestly I've never seen any interactive client that forbids C-z, so
ignoring it my default looks strange to me.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>