Remove entities from CSV entities export

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

Requires export#13 (closed)

Database exports no longer include the entity table, so the arkindex export entities command needs to be updated:

• The entity_id column is renamed transcription_entity_id and contains the TranscriptionEntity ID instead of the entity ID
• The entity_value column now contains the portion of the transcription text between offset and offset + length
• The entity_metas column is removed