GatherMetadataJob should raise an error when subject.sex or subject.genotype are null

Pups who are marked dead before sex/genotyping is performed are apparently given a subject_id but they should not be running in behavior experimenters or having SPIM done, etc. It's likely people are making typos that cause these subject_ids to get pulled in. We should prevent that from having and we should also look into whether the metadata-service can return the death date that LAS stores, which would be another check against this.