**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/hooks/bigquery.py
"""
        Helper method for fetchone, which returns the next row from a buffer.
        If the buffer is empty, attempts to paginate through the result set for
        the next page, and load it into the buffer.
        """
        if not self.job_id:
            return None
        if not self.buffer:
            if self.all_pages_loaded:
                return None
            query_results = (
                self.service.jobs()
                .getQueryResults(
                    projectId=self.project_id,
                    jobId=self.job_id,
                    location=self.location,
                    pageToken=self.page_token,
                )
                .execute(num_retries=self.num_retries)
            )
            if 'rows' in query_results and query_results['rows']:
                self.page_token = query_results.get('pageToken')
                fields = query_results['schema']['fields']
                col_types = [field['type'] for field in fields]
                rows = query_results['rows']
                for dict_row in rows:
                    typed_row = [_bq_cast(vs['v'], col_types[idx]) for idx, vs in enumerate(dict_row['f'])]