Simplify BigQuery Destination Setup

[nataliekwong]

Tell us about the problem you're trying to solve

We ask for a few inputs with the BigQuery destination that users aren't used to selecting. We can make it clearer what the impact of selecting these options will be for the user.

Describe the solution you’d like

Transformation Query Run Type: this is not typically asked of the user. The current help text does not make it intuitive to what the selection will change. A user said “it seems like from this help text, there’s no harm in choosing batch... Right?”
Google BigQuery client chunk size this is also not typically asked of the user. The label and description is wordy - it would help to simplify what this actually means. The link to the external site has no mention of "chunk size", so it's not easy for the user to understand how to find more information about it on this page. No one explicitly got tripped up here because it was just left to the default value.