## What
This PR fixes a regression tied to the new relation format refactoring.
I'm also slightly improving the performance by decreasing the number of
queries.
## Considerations
1. I've started adding an integration test to cover relation creation
and deletion but we are still using the r`elation-metadata.service` to
create a relation and the `field-metadata.service` to delete it. As we
plan to fully deprecate the `relation-metadata.service`, I did not want
to invest into writing test tooling to change it in a few weeks so I've
reverted the test
2. We are still maintaining relationMetadata table up-to-date (so
deleting them when we delete the field). relationMetadata full
deprecation is up coming but I'm waiting a bit so we don't have breaking
changes in 0.53
Charles Bochet
e94d90894b