After team discussion, see also:  https://issues.redhat.com/browse/SRVLOGIC-178, it was decided that the feature will be implemented in two parts.

1) SRVLOGIC-348Data Index modifications to register the events sent by the operator indicating that the workflow was deployed / undeployed. This information is registered in ProcessDefinition record stored in the Data Index for each workflow, and by using a new "status" field that we'll incorporate in the ProcessDefinition metadata.

When a workflow is deployed, the following value is added to the ProcessDefinition  metadata:

{
    "metadata" : { 
         "status" : "available" 
    }
}

On the other hand, when the work is undeployed, the following value is added to the ProcessDefinition metadata:

{   
    "metadata" : {
        "status" : "unavailable" 
   }
}

While the registering of the ProcessDefinition metadata is already supported, modifications were done to internally store the metadata as a JSON value, and also to support Data Index queries by using the metadata.

2) SRVLOGIC-347 Operator modifications to support the sending of the ProcessDefinition events, with the coreresponding status field = available/unavailable when the workflow is deployed/undeployed.