Db2 HADR configuration support

[SalaryTheft]

Feature and motivation

High availability is a key benefit of OpenShift/Kubernetes, and also a key concern for mission-critical sites.
But if a node goes down, Db2 pods will not be re-scheduled to another node because that's how Kubernetes handles StatefulSets and VolumeAttachments.

Db2 on OpenShift supports Db2 high availability disaster recovery (HADR) configuration with Db2uHadr CR.
It would be very handy if MAS ansible collection supports Db2 HADR configuration as a option.

Usage example

db2_hadr role variable (True/False)

[durera]

I have created an idea to formalize this RFE here: https://ibm-ai-apps.ideas.ibm.com/ideas/MASCOM-I-112

We can't really do anything in the Ansible collection without a commitment/plan to support Db2 HADR in MAS itself.