Migration of old identities

I think we should import at least the old identities names in the Ğ1v2 genesis so that their incoming or outgoing certifications point to an IdtyIndex linked to an actual identity and to avoid having to ask the indexers to make the link between v1 and v2 data. By importing also their owner_key, it also makes easier to tell if a given genesis account is a random one or belongs to an actual identity (even not member). It comes with an increase of size of the genesis (today 3620 old identities vs 7278 member identities), but I think it’s totally worth it.

So currently here is an example of the identities field of the genesis:

"identities": [
  {
    "name": "OldUser",
    "certs": [
      [
        "poka",
        4590088
      ],
      [
        "HugoTrentesaux",
        1597492
      ]
    ],
    "expire_on": 0,
    "owner_key": "5CJKhFCpdSpumgWjSZ3TQmejJuHV6iELJrtdrfs38SXuiQeB",
    "balance": 999999
  },
  {
    "name": "HugoTrentesaux",
    "expire_on": 1000,
    "balance": 2747617,
    "owner_key": "5Dq8xjvkmbz7q4g2LbZgyExD26VSCutfEc6n4W4AfQeVHZqz",
    "old_owner_key": "5Dq8xjvkmbz7q4g2LbZgyExD26VSCutfEc6n4W4AfQeVHZqz",
    "next_creatable_identity_on": 10,
    "certs": [
      [
        "poka",
        3073250
      ]
    ]
  },
  {
    "name": "Maaltir",
    "expire_on": 10,
    "balance": 310578,
    "owner_key": "5GosZYTL75W3J4K8JvtRjeNBrYAz3tgEqxV1Si5XPurJScvz",
    "old_owner_key": "5GosZYTL75W3J4K8JvtRjeNBrYAz3tgEqxV1Si5XPurJScvz",
    "next_creatable_identity_on": 20,
    "certs": [
      [
        "OldUser",
        9248690
      ]
    ]
  },
  {
    "name": "poka",
    "expire_on": 10,
    "balance": 1737099,
    "owner_key": "5CQ8T4qpbYJq7uVsxGPQ5q2df7x3Wa4aRY6HUWMBYjfLZhnn",
    "old_owner_key": "5CQ8T4qpbYJq7uVsxGPQ5q2df7x3Wa4aRY6HUWMBYjfLZhnn",
    "next_creatable_identity_on": 33,
    "certs": [
      [
        "HugoTrentesaux",
        684224
      ]
    ]
  }
],

Note that the expire_on field of the OldUser is set to 0 meaning that his identity is no longer member at the genesis.