Keycloak should permit to create realms instead of importing one

Actually, the deployment only support importing an existing realm:

• a realm-secret is created in deploy from the realm-export.json file
• keycloak-values.yaml contains:
  • extraEnv variable KEYCLOAK_IMPORT with /realm/realm-export.json value
  • readinessProbe check the imported realm /auth/realms/mim
  • extraVolumeMounts mounts the realm-secret under /realm

I propose:

• to add a vars.ini configuration option like:

  [keycloak]
  #Keycloak realm name
  realm=mim
  realmImport=true
  realmImportFile=/machin/bidule/realm-export.json

• remove the realm import stuffs from keycloak-values.yaml if realmImport is false
• create the realm manually with the keycloak REST API (with checks to avoid multi-create?)
• manage laboite client as any other client
• make keycloak.realmImport=false the default since the import is specific to PCLL/APPS environments (this is a breaking change)

Notes for laboite

• User registration should be enabled by default
• Client for laboite must be of access type public