**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
if var_name is None:
            return ""
        else:
            return "Format exception for {var}: ".format(var=var_name)
    if table_input.count('.') + table_input.count(':') > 3:
        raise Exception(
            ('{var}Use either : or . to specify project ' 'got {input}').format(
                var=var_print(var_name), input=table_input
            )
        )
    cmpt = table_input.rsplit(':', 1)
    project_id = None
    rest = table_input
    if len(cmpt) == 1:
        project_id = None
        rest = cmpt[0]
    elif len(cmpt) == 2 and cmpt[0].count(':') <= 1:
        if cmpt[-1].count('.') != 2:
            project_id = cmpt[0]
            rest = cmpt[1]
    else:
        raise Exception(
            ('{var}Expect format of (<project:)<dataset>.<table>, ' 'got {input}').format(