**Apache Airflow version**: 1.10.*
**BackPort Packages version**: 2020.10.5rc1

**What happened**:

`BigQueryInsertJobOperator` tries to start a BigQuery job by specifying a job_id which is a combination of `dag_id`, `task_id`, `execution_date` and an additional `uniqueness_suffix`.

https://github.com/apache/airflow/blob/master/airflow/providers/google/cloud/operators/bigquery.py#L2072

However, because BigQuery only accepts alphanumeric (in additon to dashes and underscore) characters then, if a DagID contains a version number whcih includes a `.` character then this will cause the task to fail.

https://cloud.google.com/bigquery/docs/running-jobs#generate-jobid

**How to reproduce it**:
Create a DAG with the name `my-dag-v1.0`.
airflow/providers/google/cloud/operators/bigquery.py
gcs_bucket, gcs_object = _parse_gcs_url(self.gcs_schema_object)
            gcs_hook = GCSHook(
                google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
                delegate_to=self.delegate_to,
                impersonation_chain=self.impersonation_chain,
            )
            schema_fields = json.loads(gcs_hook.download(gcs_bucket, gcs_object).decode("utf-8"))
        else:
            schema_fields = self.schema_fields
        try:
            self.log.info('Creating table')
            table = bq_hook.create_empty_table(
                project_id=self.project_id,
                dataset_id=self.dataset_id,
                table_id=self.table_id,
                schema_fields=schema_fields,
                time_partitioning=self.time_partitioning,
                cluster_fields=self.cluster_fields,
                labels=self.labels,
                view=self.view,
                encryption_configuration=self.encryption_configuration,
                table_resource=self.table_resource,
                exists_ok=False,
            )
            self.log.info(
                'Table %s.%s.%s created successfully', table.project, table.dataset_id, table.table_id
            )
        except Conflict:
            self.log.info('Table %s.%s already exists.', self.dataset_id, self.table_id)
class BigQueryCreateExternalTableOperator(BaseOperator):