support for materialized views

[tswast]

Another table type: https://cloud.google.com/bigquery/docs/materialized-views-intro

[tswast]

Test resource for reference:

{
  "kind": "bigquery#table",
  "etag": "7Ct2d8SG3CQbHnRXL1OAhw==",
  "id": "swast-scratch:my_dataset.tx_names",
  "selfLink": "https://content-bigquery.googleapis.com/bigquery/v2/projects/swast-scratch/datasets/my_dataset/tables/tx_names",
  "tableReference": {
    "projectId": "swast-scratch",
    "datasetId": "my_dataset",
    "tableId": "tx_names"
  },
  "schema": {
    "fields": [
      {
        "name": "total",
        "type": "INTEGER"
      },
      {
        "name": "state",
        "type": "STRING"
      },
      {
        "name": "gender",
        "type": "STRING"
      },
      {
        "name": "year",
        "type": "INTEGER"
      },
      {
        "name": "name",
        "type": "STRING"
      }
    ]
  },
  "numBytes": "11045428",
  "numLongTermBytes": "0",
  "numRows": "356150",
  "creationTime": "1606751841803",
  "lastModifiedTime": "1606751852031",
  "type": "MATERIALIZED_VIEW",
  "location": "US",
  "materializedView": {
    "query": "SELECT SUM(number) AS total, state, gender, year, name\nFROM swast-scratch.my_dataset.usa_names\nWHERE state = 'TX'\nGROUP BY state, gender, year, name",
    "lastRefreshTime": "1606751842496",
    "enableRefresh": true,
    "refreshIntervalMs": "1800000"
  }
}