Provide onramp for OCP 3.y broker customers to OCP 4.y

At the moment we have customers using our classic A-MQ Broker on OpenShift 3.y via the A-MQ 6.3 xPaaS container image along with templates, as well as customers using our AMQ 7.y Broker container image plus templates. Very soon those customers will be seeking a path forward onto OpenShift 4.y for which the installation and ongoing management solution is an operator.

Under this epic we should identify further steps to be taken to ensure this transition happens as smoothly as possible.