Redis: sub-queues should inherit all of password settings

Enable sub-queue items to inherit password:{} items for those they do not have present. Such as enabled, secret, or key.

E.g.:

global:
  redis:
    password:
      enabled: true
      secret: xyz
    cache:
      password:
        secret: abc

Should result in

global:
  redis:
    password:
      enabled: true
      secret: xyz
    cache:
      password:
        enabled: true
        secret: abc

Closes #2030 (closed)

Closes #2030 (closed)