Fix switching from dynamic to fixed storage mode [WAL-2895]
Fix switching from dynamic to fixed storage mode [WAL-2895]

Allow to store volume-type-based component prices during the switch.

opennode/nodeconductor-assembly-waldur,opennode/waldur-mastermind,opennode/nodeconductor-assembly-waldur,opennode/waldur-mastermind,opennode/nodeconductor-assembly-waldur,opennode/waldur-mastermind,opennode/waldur-mastermind