Rename hook bigquery function _bq_cast to bq_cast

[pankajastro]

Recently, I have started using hook bigquery function _bq_cast but I'm afraid that this might get changed silently since it is a private function so I want to rename it to bq_cast

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[uranusjr]

If we decide to make this function public, I also wonder if it’d be a good idea to move the function to somewhere in utils instead.

[pankajastro]

If we decide to make this function public, I also wonder if it’d be a good idea to move the function to somewhere in utils instead.

I was not able to find the right place to add it to utils. shall I create utils/provider.py or utils/type_cast.py?

[uranusjr]

Maybe airflow.providers.google.cloud.utils.bigquery? There’s already a bigquery_get_data so maybe it might make sense in there too…? Not sure.

[pankajastro]

Maybe airflow.providers.google.cloud.utils.bigquery? There’s already a bigquery_get_data so maybe it might make sense in there too…? Not sure.

for this PR scope, I'll be in favour of keeping it in airflow.providers.google.cloud.utils.bigquery latter maybe we can also move bigquery_get_data in airflow.providers.google.cloud.utils.bigquery