Add policy_document_id and policy_generation_requested_at columns to
cookie_banners and backfill banners that already have a published
version, so existing live banners get a policy on the worker's first
pass.
Flag the banner for policy generation inside the publish transaction so
generation is requested only when a cookie banner version is published,
not on draft edits. Fold policy_document_id into the existing Update so
the upcoming worker can persist the generated document id with the
scope it already holds.
Signed-off-by: Émile Ré <emile@probo.com>
f6eeeb675f