Database schema changes

• Add suffix __id to columns sphn_hasSubjectPseudoIdentifier and sphn_hasDataProvider/spnh_hasDataProviderInstitute
• Add non-nullable column sphn_hasDataProvider__id/sphn_hasDataProviderInstitute__id to table sphn_SubjectPseudoIdentifier (won't be considered in any filtering and won't be extracted)

MR as draft in view of the review meeting. If no complains received from the UH then we can merge it.