Remove hardened from bb-common

In the process of integrating bb-common AuthorizationPolicies with Kiali, it became difficult to maintain the existing configuration pattern where by istio.hardened.enabled=true would enable REGISTRY_ONLY outboundTrafficPolicy and enable AuthorizationPolicies for the package while also maintaining individual flags for enabling AuthorizationPolcies and Sidecar configuration.

In order to address this confusion we should remove the hardened config option from bb-common and replace with explicit configuration for things it controlled, so previously a package would set:

istio:
  hardened: 
    enabled: true
  customServiceEntries: []
  customAuthorizationPolicies: []

but will now move to this configuration:

istio:
  sidecar:
    outboundTrafficPolicyMode: REGISTRY_ONLY
  authorizationPolicies:
    enabled: true
    custom: []
  serviceEntries:
    custom: []