[Feature Request]: Add with .withFormatFunction() equivalent to Python SDK BigQueryIO

[chishankar-work]

What would you like to happen?

Support customization for dynamic destinations when using Python SDK, BigQueryIO to allow users to embed destination tables without writing it to BigQuery.

A current workaround would to add destionation_table_name as a dummy column in the TableRow object and then use then set ignore_unkown_columns=True and then pass a callable table=getTableDestinationFn that gets called on each element and returns the destination_table_name.

Issue Priority

Priority: 3 (nice-to-have improvement)

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