[625] Part 2, Ingest new visa sponsorship field

[elceebee]

Context

This is the second PR for this ticket. See the first PR for a detailed description

Changes proposed in this pull request

Guidance to review

Things to check

• If the code removes any existing feature flags, a data migration has also been added to delete the entry from the database
• This code does not rely on migrations in the same Pull Request
• If this code includes a migration adding or changing columns, it also backfills existing records for consistency
• If this code adds a column to the DB, decide whether it needs to be in analytics yml file or analytics blocklist, if included inform data insights team of the changes
• If this code adds a column that may include PII, the sanitise.sql script and 0025-protecting-personal-data-in-production-dump.md ADR have been updated
• API release notes have been updated if necessary
• If it adds a significant user-facing change, is it documented in the CHANGELOG?
• Attach the PR to the Trello card

[elceebee]

Ingest new visa sponsorship attribute into Apply - [Apply]

[github-actions]

You have one or more flakey tests on this branch! ❄️ ❄️ ❄️

Failed 1 out of 3 times at ./spec/system/provider_interface/candidate_pool/provider_views_candidate_pool_list_spec.rb:15: ⚠️ Expected �[33m["G***** V*****", "T***** B*****"]�[0m to eq �[35m["T***** B*****", "G***** V*****"]�[0m.

�[37mDiff:�[0m

�[34m┌ (Key) ──────────────────────────┐�[0m
�[34m│ �[0m�[35m‹-› in expected, not in actual�[0m�[34m │�[0m
�[34m│ �[0m�[33m‹+› in actual, not in expected�[0m�[34m │�[0m
�[34m│ �[0m‹ › in both expected and actual�[34m │�[0m
�[34m└─────────────────────────────────┘�[0m

[
�[35m- "T***** B*****",�[0m
"G***** V*****",
�[33m+ "T***** B*****"�[0m
]