Goal: 

Based on the agreed CRD design, implement a top level notification bus definition for the whole OSCP deployment, then each listed in the components service operator inherits that, if the user does not override in the service specific template (SpecCore) in the OpenStackControlPlane CR.

Acceptance Criteria:

• PR has been merged, unit tests created and passing
• Default values for notifications retain status quo to provide no upgrade impact for involved services