Since the 10.5 split of the privileges, the required GRANTs
for various mariabackup operations has changed.
In the addition of tests, a number of mappings where incorrect:
The option --lock-ddl-per-table didn't require connection admin.
The option --safe-slave-backup requires SLAVE MONITOR even without
the --no-lock option.
If required privilege is missing, dump the output from "SHOW GRANTS"
into mariabackup log.
This will help troubleshooting, and make the bug reproducible.
ported privilege checking from xtrabackup.
Now, mariabackup would terminate early if either RELOAD or PROCESS privilege
is not held, not at the very end of backup
The behavior can be disabled with nre setting --check-privileges=0.
Also , --no-lock does not need all of these privileges, since it skips
FTWRL and SHOW ENGINE STATUS INNODB.