Fix for Office factory
Fix for Office factory

Since I only ran a subset of examples, I never experienced any issues
with the Office entity code uniqueness clashes. But once I started to
run full suite, the clashes became obvious and annoying. This commit
ensures that the entity_code truly is unique.

ministryofjustice/fr-staffapp,ministryofjustice/fr-staffapp,ministryofjustice/fr-staffapp,ministryofjustice/fr-staffapp