Destination BigQuery Denormalized : workaround for #14023

[DoNotPanicUA]

Tell us about the problem you're trying to solve

Right now, we cannot release a version without backward compatibility. Such change can affect existing cloud users and their production connections.
To improve our current version handling for such cases, we designed improvements for the Airbyte. But they are blocked till new metadata handling for the cloud is still under development.
Until then, we should handle both implementations inside connectors to avoid affecting existing users. (This strategy is confirmed by @grishick)

Describe the solution you’d like

#14023 (comment)
For PR #14023 we need to implement the old and new versions of the processing and use the proper one for existing connections (with old schema) and for all others (which can use new).