[AIRFLOW-4233] Remove Template Extension from Bq to GCS Operator (#5456)
[AIRFLOW-4233] Remove Template Extension from Bq to GCS Operator (#5456)

The issue happens when we have destination url ending with .sql.
It is related to the defined template extension template_ext = ('.sql',)

The operator looks for jinja template, however, it's an output path, so the
file is not found when looking for any jinja template syntax.

The BigQueryToCloudStorageOperator doesn't have sql parameter as it doesn't
work with queries at all. It takes only tables.
danielvdende/incubator-airflow,cfei18/incubator-airflow,Fokko/incubator-airflow,nathanielvarona/airflow,DinoCow/airflow,mrkm4ntr/incubator-airflow,apache/airflow,wooga/airflow,lyft/incubator-airflow,mrkm4ntr/incubator-airflow,sekikn/incubator-airflow,mistercrunch/airflow,wooga/airflow,apache/airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,apache/airflow,Acehaidrey/incubator-airflow,DinoCow/airflow,mtagle/airflow,bolkedebruin/airflow,danielvdende/incubator-airflow,mrkm4ntr/incubator-airflow,Fokko/incubator-airflow,dhuang/incubator-airflow,spektom/incubator-airflow,wileeam/airflow,spektom/incubator-airflow,wooga/airflow,airbnb/airflow,cfei18/incubator-airflow,nathanielvarona/airflow,sekikn/incubator-airflow,apache/incubator-airflow,Acehaidrey/incubator-airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,cfei18/incubator-airflow,wileeam/airflow,nathanielvarona/airflow,spektom/incubator-airflow,dhuang/incubator-airflow,mtagle/airflow,nathanielvarona/airflow,nathanielvarona/airflow,apache/airflow,nathanielvarona/airflow,wileeam/airflow,mtagle/airflow,Fokko/incubator-airflow,apache/airflow,mistercrunch/airflow,apache/incubator-airflow,spektom/incubator-airflow,Acehaidrey/incubator-airflow,DinoCow/airflow,DinoCow/airflow,Acehaidrey/incubator-airflow,airbnb/airflow,bolkedebruin/airflow,mrkm4ntr/incubator-airflow,Acehaidrey/incubator-airflow,wileeam/airflow,dhuang/incubator-airflow,Acehaidrey/incubator-airflow,mistercrunch/airflow,mistercrunch/airflow,bolkedebruin/airflow,Fokko/incubator-airflow,wooga/airflow,danielvdende/incubator-airflow,bolkedebruin/airflow,apache/incubator-airflow,lyft/incubator-airflow,cfei18/incubator-airflow,airbnb/airflow,dhuang/incubator-airflow,mtagle/airflow,lyft/incubator-airflow,airbnb/airflow,cfei18/incubator-airflow,apache/airflow,cfei18/incubator-airflow,lyft/incubator-airflow,sekikn/incubator-airflow,danielvdende/incubator-airflow,apache/incubator-airflow