**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
return [t.reference.to_api_repr() for t in tables]
    @GoogleBaseHook.fallback_to_default_project_id
    def delete_dataset(
        self,
        dataset_id: str,
        project_id: Optional[str] = None,
        delete_contents: bool = False,
        retry: Retry = DEFAULT_RETRY,
    ) -> None:
        """
        Delete a dataset of Big query in your project.
        :param project_id: The name of the project where we have the dataset.
        :type project_id: str
        :param dataset_id: The dataset to be delete.
        :type dataset_id: str
        :param delete_contents: If True, delete all the tables in the dataset.
            If False and the dataset contains tables, the request will fail.
        :type delete_contents: bool
        :param retry: How to retry the RPC.
        :type retry: google.api_core.retry.Retry
        """
        self.log.info('Deleting from project: %s  Dataset:%s', project_id, dataset_id)
        self.get_client(project_id=project_id).delete_dataset(
            dataset=DatasetReference(project=project_id, dataset_id=dataset_id),
            delete_contents=delete_contents,
            retry=retry,
            not_found_ok=True,
        )
    @GoogleBaseHook.fallback_to_default_project_id
    def create_external_table(  #