at-voc-new:document-type

[AchillesDougalis]

codelist at-voc-new:document-type  needs to be moved to epo:core, as it is used by Pre-award (part of ePO core module),
and by the eCatalogue and eOrdering modules.

There is also a decision to be made regarding the contents of the codelist. Specifically, it was discovered that a similar concept used by PEPPOL, documentStatusCode, uses some values that do not exist in at-voc-newdocument-status. We need to enumerate these values along with other values that are currently needed by the eCatalogue and eOrdering modules. Then, we need to choose if we shall keep all the values in the at-voc-new:document-type codelist, or if new codelists are needed.

 Also, the predicate epo-cat:hasDocumentType that conects ePO to at-vocnew:document-type Should be renamed to "epo:documentUsedInPublicProcurement".