Mechanism to hook up event listener into Teiid runtime

It would be to useful allow the installation of custom listeners since we don't have a global vdb table that could have customizable triggers. This could cover for example custom strategies for external materialization initialization.

This would also help in where an application wants to listen to when a VDB was added, made active, destroyed so that it can handle those events as required by the application.

Please see the thread below for the context & details

https://community.jboss.org/message/756060