feat(ingest, backend): Modify ingest to handle curation of ingested sequences

[anna-parker]

resolves #

preview URL: https://insdc-approve-anya.loculus.org/

Summary

Screenshot

PR Checklist

• [ ] Curate a metadata field make sure ingest doesnt change it Curated a random sequence from NIH - its nice to see that even if the uploaded metadata includes indsc_ingest_user as submitter this is overwritten by the actual submitter
• [ ] Curate a sequence make sure ingest doesnt change it
• [ ] Somehow test what happens if you curate a sequence/metadata field and then ingest modifies it again
• [ ] The implemented feature is covered by an appropriate test.