Resolve "Filter dataset by datasetType and nest them"

Closes #361 (closed) This MR adds the parameter nested to the endpoint: /catalogue/{sessionId}/dataset`

Example: /catalogue/5913dfe9-d506-4e3e-8e59-7c0ee7c79f6f/dataset?investigationId=9&datasetType=acquisition&nested=true

When nested === "true" then the outputDatasets will be populated independently of their datasetType