🎉 Destination BigQuery: Use byte-based buffering batching

[alexandr-shegeda]

Tell us about the problem you're trying to solve

We need to implement byte-based buffering of records rather than record-number-based buffering for the BigQuery destination. This makes the connector much more resilient to pathological data like very wide rows. This fix should be applied to both INSERT and Bulk sync mode if it is not already applied.

Describe the solution you’d like

• find a way to replace MAX_BATCH_SIZE with MAX_BATCH_SIZE_BYTES
• refactor related functionality
• cover the changes with proper tests
• raise PR and pass to review

Describe the alternative you’ve considered or used

This PR fixed an important flaw in how JDBC destinations using the INSERT sync mode: it started using byte-based buffering of records instead of record-number-based buffering.

Additional context

Add any other context or screenshots about the feature request here.

It is super important that we consider DRYing our solution as much as possible because otherwise, we might need to implement the same thing repeatedly, which would be really bad.