Excavate worker version IDs from corpus exports

arkindex/documents/export/classification.sql

arkindex/documents/export/element.sql

arkindex/documents/export/entity.sql

arkindex/documents/export/indexes.sql

arkindex/documents/export/metadata.sql

arkindex/documents/export/structure.sql

arkindex/documents/export/transcription.sql

arkindex/documents/export/transcription_entity.sql

arkindex/documents/export/worker_version.sql

arkindex/documents/fixtures/data.json

arkindex/documents/management/commands/build_fixtures.py

arkindex/documents/management/commands/load_export.py

arkindex/documents/tests/commands/test_load_export.py

arkindex/documents/tests/tasks/test_export.py

arkindex/documents/tests/test_children_elements.py

arkindex/documents/tests/test_corpus_elements.py

arkindex/documents/tests/test_edit_transcriptions.py

arkindex/documents/tests/test_transcriptions.py