**Description**

`BigQueryInsertJobOperator` requires the submission of a `configuration` parameter in the form of a dict.  Unfortunately, if this contains a large SQL query - especially one that is formatted with new lines - then this cannot currently be rendered very nicely in the UI.

<img width="1670" alt="Screenshot 2021-07-15 at 15 39 33" src="https://user-images.githubusercontent.com/967119/125806943-839d57a9-d4a0-492d-b130-06432b095239.png">

**Use case / motivation**

The issue with this is that it's impossible to copy and paste the rendered query out of the Airflow UI, into a BigQuery browser and run it without lots of manual edits which is time wasted when troubleshooting problems.

**Are you willing to submit a PR?**

Yes.  My current thought process around this would be to add an optional SQL parameter to the operator which, if provided, would be added into the configuration and could therefore have its own template field and SQL renderer.

e.g.

<img width="1570" alt="Screenshot 2021-07-14 at 14 18 09" src="https://user-images.githubusercontent.com/967119/125808200-5f30b8f4-4def-48a7-8223-82afdc65c973.png">


airflow/providers/google/cloud/operators/bigquery.py
super().on_kill()
        if self.hook is not None:
            self.log.info('Cancelling running query')
            self.hook.cancel_query()
class BigQueryCreateEmptyTableOperator(BaseOperator):
    """
    Creates a new, empty table in the specified BigQuery dataset,
    optionally with schema.
    The schema to be used for the BigQuery table may be specified in one of
    two ways. You may either directly pass the schema fields in, or you may
    point the operator to a Google Cloud Storage object name. The object in
    Google Cloud Storage must be a JSON file with the schema fields in it.
    You can also create a table without schema.
    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:BigQueryCreateEmptyTableOperator`
    :param project_id: The project to create the table into. (templated)
    :type project_id: str
    :param dataset_id: The dataset to create the table into. (templated)
    :type dataset_id: str
    :param table_id: The Name of the table to be created. (templated)
    :type table_id: str
    :param table_resource: Table resource as described in documentation:
        https://cloud.google.com/bigquery/docs/reference/rest/v2/tables#Table
        If provided all other parameters are ignored.