INT-3350: Register IntRMHM, if Servlet is Present

https://jira.spring.io/browse/INT-3350
INT-3349 BeanFactory Propagation

JIRA: https://jira.spring.io/browse/INT-3349

Several FactoryBeans did not propagate the BeanFactory
to their created object(s). Beans that create messages
must have access to a bean factory to get the
message builder factory.

Fix the FactoryBeans and add a mock FB to all tests that
need one.

Add a runtime environment variable to make any infractions
fatal. This should be set to `true` on CI builds and on
framework developer environments.