Sink to BigQuery with google pubsub sink

[docteurklein]

Is your feature request related to a problem? Please describe.

Given the level of integration with pubsub between the different GCP components (cloud run, eventarc, dataflow, bigquery, workflows, ...), having a pubsub sink would be highly beneficial.
I'm currently missing this to take advantage of the pubsub bigquery CDC feature as documented here: https://cloud.google.com/pubsub/docs/bigquery.

Describe the solution you'd like

I'd like a sink wose definition would look like:

CREATE SINK sink1 FROM mv1
WITH (
   connector='google_pubsub',
   topic='topic1'
)
FORMAT PLAIN ENCODE JSON; -- possibly AVRO  [1]

[1] https://cloud.google.com/pubsub/docs/samples/pubsub-publish-avro-records

Describe alternatives you've considered

I tried to use the native RW bigquery sink, but it's using the legacy tabledata.insertAll method, which is not compatible with the CDC message ingestion.

Additional context

opening the issue here as discussed in https://github.com/orgs/risingwavelabs/discussions/15237

[neverchanje]

#16363 will resolve this issue.