core/metadata: Improve invalid checksum logging
core/metadata: Improve invalid checksum logging

Better pass the doc to the logger instead of stringifying it ourselves,
so we can filter on its properties using jq.

cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,nono/cozy-desktop,nono/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,nono/cozy-desktop,nono/cozy-desktop