Support transcription orientation in base worker

Depends arkindex/backend#855 (closed), arkindex/backend#854 (closed), arkindex/backend#853 (closed), arkindex/backend#852 (closed)

Once all required endpoint support that feature, we'll need to support that optional field in base worker. All methods from TranscriptionMixin should support that field.

You will also need to patch the cache database structure to cleanly support it, and bump the version.

This work can either be done in a single MR, or split by endpoint.