Follow-up Task : Git Issue # 4049 - Get Process Instance API response is updated so that it returns the Process Definition Key.

[Nandanrshenoy]

This is a follow-up ticket against the Git Issue link : [Get Process Instance API to return Process Definition Key value in the API response · Issue #4049 : https://github.com//issues/4049 ]

Camunda Forum Discussion : https://forum.camunda.io/t/is-there-a-way-get-the-process-definition-key-by-processinstanceid/9066

Through this follow-up ticket I will be investigating if we can simplify the selectProcessInstanceByQueryCriteriaSql and selectExecutionsByQueryCriteriaSql since the processDefinitionKey will be a column of the Execution table.