WIP: DNM: Add support for an array of equalogic backends

Modifies the AttributeParamStorage to support an array of items
So, I think maybe LVM should default to "false" along with everything else. If it doesn't get passed in, it will be deleted (I think) from the parameters table. So, that should cover the situation where is "goes away". I will need to test that scenario. Otherwise, in the validation function, I will check if the deployment is HA, and if it is, removed :backend_lvm from the list.