Get error in response if tg-crud can not be accessed via IDIOM images
We need to get correct error messages if no metadata can be get from tg-crud, and not deliver different ID metadate (please compare header and record ID!!), see https://dev.textgridlab.org/1.0/tgoaipmh/oai?verb=GetRecord&identifier=textgrid%3A3vcgs.0&metadataPrefix=oai_idiom_mets