Add BigQuery driver to the `sql_*` components

[mihaitodor]

I made some small enhancements to this driver a while back:

• https://github.com/go-gorm/bigquery/pull/13
• https://github.com/go-gorm/bigquery/pull/12

Since this driver is owned by the folks behind GORM, I assume it will continue to be maintained.

I also put in some work to clean up the GCP component documentation a bit.

TODO

• [x] Add tests based on https://github.com/goccy/bigquery-emulator
• [x] Consider waiting for https://github.com/go-gorm/bigquery/pull/19 to get merged before merging this if you'd like to avoid the go.sum spam.
• [ ] Wait for a new release of https://github.com/go-gorm/bigquery

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