Implement a SendGrid access-review driver that fetches teammates
from the SendGrid API and maps them into AccountRecord values.
Register SendGrid as a connector provider, expose it through the
connector provider enum, and add a migration that extends the
connector_provider type with SENDGRID.
Cover the new driver with a VCR-backed fixture test and helper
tests for role and response-shape handling to keep parsing robust.
Signed-off-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>