Add a way to define and switch different timeouts for primary and replicate during failover

There are good reasons to have different settings for various timeouts like:

• max_statement_time
• wait_timeout
• lock_wait_timeout
• innodb_lock_wait_timeout
• etc

for primary/master server vs slave/replica. When failover happens these settings should be changed and assuming Maxscale does and controls failover process, it should get options to do this. I mean separate settings for "primary" and "replica" timeouts or maybe any/all global variables to enforce on a node that switches to that status.