Remove entities from exports

https://redmine.teklia.com/issues/11004

In order to remove entities from Arkindex, we need to remove them from database exports:

• export_version is bumped to 11
• The entity table is removed
• transcription_entity.entity_id becomes transcription_entity.type_id
• metadata.entity_id is removed
• arkindex load_export only supports exports in version 11