New operation field needs to be added to cps temporal records list response.

Response reference from Istanbul release: https://wiki.onap.org/display/DW/CPS-251++Define+REST+Query+interface+for+Temporal+service#CPS251DefineRESTQueryinterfaceforTemporalservice-ResponseresponseBody

AC:

• operation is provided for each record returned by rest api search history endpoints:
  • by dataspace and anchor: https://github.com/onap/cps-cps-temporal/blob/master/openapi/swagger/openapi.yml#L39
  • by dataspace and schema set: https://github.com/onap/cps-cps-temporal/blob/master/openapi/swagger/openapi.yml#L86
• Documentation is updated in RTD for the overall feature (event structure, open api definition, upgrade from istanbul in deployment section)
  • https://docs.onap.org/projects/onap-cps-cps-temporal/en/latest/index.html#master-index
  • https://docs.onap.org/projects/onap-cps-cps-temporal/en/latest/content/modeling.html
  • https://docs.onap.org/projects/onap-cps-cps-temporal/en/latest/content/design.html
  • https://docs.onap.org/projects/onap-cps-cps-temporal/en/latest/content/deployment.html