[Enhancement] Handle the multivalue field properly

[penghuo]

Currently, we the field has multiple value, SQL/PPL can't handle it properly.

PUT objectsit/_doc/1
{
  "name": ["test1", "test2"],
  "ids": [1, 2],
  "accounts": [
    {
      "id": 1
    },
    {
      "id": 2
    }
  ]
}
POST /_opendistro/_sql
{
  "query": """
    SELECT name, ids, accounts
    FROM objectsit
  """
}

{
  "schema": [
    {
      "name": "name",
      "type": "text"
    },
    {
      "name": "ids",
      "type": "long"
    },
    {
      "name": "accounts",
      "type": "object"
    }
  ],
  "datarows": [
    [
      "",
      0,
      {}
    ]
  ],
  "total": 1,
  "size": 1,
  "status": 200
}