chore(engine-rest): add hal link assertions

related to CAM-2940
chore(cmmn/history): remove failed/suspended api methods from history

related to CAM-2841
chore(engine): remove suspended/failed from historic case instance

- removes the methods isFailed()/isSuspended() from the interface
  HistoricCaseInstance
- removes the methods for querying these states from the query interface
- adapts the REST API accordingly

related to CAM-2840
chore(engine-rest): remove POST for historic case activity instances

- the POST query does not offer more functionality than the GET query
  so it is not required

related to CAM-2842
fix(engine): fix constant name typo
chore(engine): execute HistoricVariableInstanceTest on all databases
feat(engine): enable to query historic variable instances by case ids

- query historic variable instance by case instance/execution id
- query historic detail by case instance/execution id
- query historic case instance by case variable value

related to #CAM-2843