[lib][schema] Make kavlan hashes optional
This allows the schema to validate even when kavlan is set to false for a cluster (such as when initially installing a cluster).
La vérification des quotas de chaque projet est mise en place en mode non bloquant. Plus d'information sur : https://doc-si.inria.fr/pages/viewpage.action?pageId=146834656
Quota verification is enabled for projects in non-blocking mode. More information: https://doc-si.inria.fr/pages/viewpage.action?pageId=146834656
This allows the schema to validate even when kavlan is set to false for a cluster (such as when initially installing a cluster).