To provide feature equality between MySQL and MariaDB the same feature as implemented in #14858 (setting a max_execution_time for live queries) should also be supported when using MariaDB.

MariaDB uses a different syntax and seconds instead of milliseconds, but apart from that, the feature should work the same.

See https://mariadb.com/kb/en/library/aborting-statements/ for more information about this.

ping @tomper00 and @jorgeuos