Resolve "Populate dataset technique"

Closes #565 (closed)

Rules to be added to ICAT

• R SELECT datasetTechnique FROM DatasetTechnique datasetTechnique JOIN datasetTechnique.dataset dataset JOIN dataset.investigation investigation where investigation.doi <> null and investigation.releaseDate < CURRENT_TIMESTAMP
• R SELECT datasetTechnique FROM DatasetTechnique datasetTechnique JOIN datasetTechnique.dataset dataset JOIN dataset.dataCollectionDatasets dataCollectionDatasets JOIN dataCollectionDatasets.dataCollection dataCollection WHERE dataCollection.doi <> null
• R DatasetTechnique<->Dataset<->Investigation<->InvestigationUser<->User[name=:user]
• R DatasetTechnique<->Dataset<->Investigation<->InvestigationInstrument<->Instrument<->InstrumentScientist<->User[name=:user]
• R Technique

New endpoint: GET /catalogue/techniques/