vault.to_disk: Rename content_get call to content_get_data
This also adds types and simplify the existing code.
Test Plan
tox (failing until storage release > 0.12)
Migrated from D3730 (view on Phabricator)
Staging instance, all changes can be removed at any time
This also adds types and simplify the existing code.
tox (failing until storage release > 0.12)
Migrated from D3730 (view on Phabricator)