Log warning if reverse name resolution takes significant time

Currently it is difficult to diagnose the Maxscale stall due to reverse DNS lookups.

Customer would like skip_name_resolve default value to be set to true.

When Slow reverse DNS lookups during authentication cause MaxScale to stall, the log output does not give an indication as to what is happening. Is it possible to add something to the log that indicates starting reverse dns lookup, and ending reverse dns lookup? And/or checking the amount of time that takes and possibly suggesting setting skip_name_resolve to be set to true.

2022-05-25 16:00:08 info : (391) [MariaDBProtocol] Client 'my_user'@'::ffff:10.180.66.24' is attempting a COM_CHANGE_USER to 'rw_user'.
2022-05-25 16:00:14 info : (216) Found matching user 'my_user'@'%' for client 'my_user'@'::ffff:10.180.66.248' with sufficient privileges.