Eliminate fault-tolerance/executor dependence on ee subsystem module

FaultToleranceContainerExecutorFactory has a compile time dep on the ee subsystem module just so it can cast the ThreadFactory it looks up in JNDI to org.jboss.as.ee.concurrent.ManagedThreadFactoryImpl before returning it as a plain old ThreadFactory.

We should avoid deps between extensions. For this one, if the cast is necessary at all (i.e. as a check that the JNDI lookup is producing something valid), a cast to javax.enterprise.concurrent.ManagedThreadFactory should suffice.