Tests that a disabled event is not enabled.
Should make the test more likely to succeed.
Tests should clean up after themselves and in the case of this event, it can cause problems with other tests.
The code previously formatted everything as `new( std::nothrow)`.
The test adds a scheduled server event, the does failover, rejoin and switchover and checks that event is manipulated correctly. Also includes a change to the monitor to fix an invalid ALTER EVENT query when the event definer has wildcard host.
