Investigate using Jobs to configure database

A kubernetes Job could be used to run the init-db.sh script (which is currently duplicated for the vs-renderer and vs-registrar Chart).

The benefits would be:

• simplicity: only the setup-job would need to run the script, no need for every Pod to check whether the DB was set up
• reduced duplicity: the init-db script could be migrated to a single place. - solved by symlink
• re-running: in helm-releases via flux, this script could be automatically re-run to sync the database with the configuration.

The post-install hook seems like a good place to do this. (also consider post-upgrade)