UI is presenting wrong storage pool sizes in clusters

the UI is calculating storage pool sizes wrongly when CEPH pools are involved.

when shared pools are present in a cluster the UI should not stack their sizes, as every VMHost will report that pool but they all point to the same storage capacity.

the vmcluster endpoint has the correct pool sizes and aggregated storage capacity:

{
    "name": "CEPH-LAB",
    "project": "cluster-lab",
    "id": 3,
    "total": {
        "cores": 2,
        "memory": 4294967296,
        "local_storage": 216409694208
    },
    "available": {
        "cores": 2,
        "memory": 4294967296,
        "local_storage": 216409694208
    },
    "vm_count": 0,
    "vmhost_count": 2,
    "version": "4.19",
    "storage_pools": {
        "local": {
            "free": 14555799552,
            "total": 14555799552
        },
        "remote": {
            "free": 201853894656,
            "total": 201853894656
        }
    },
    "used": {
        "cores": 0,
        "memory": 0,
        "local_storage": 0
    },
    "resource_uri": "/MAAS/api/2.0/vm-clusters/3"
}