Add location as App option for BigQuery

[teallarson]

Change description

Previously, because BigQuery defaults to US, we could only support US datasets. This PR adds an optional appOption to BigQuery plugin for the region or multi-region code of a BigQuery dataset, passes that as part of the connection. This is only required for users with a dataset outside the United States.

Checklists

Development

• Application changes have been tested appropriately

Impact

• Code follows company security practices and guidelines
• Security impact of change has been considered
• Performance impact of change has been considered
• Possible migration needs considered (model migrations, config migrations, etc.)

Please explain any security, performance, migration, or other impacts if relevant:

Code review

• Pull request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached where applicable.
• Relevant tags have been added to the PR (bug, enhancement, internal, etc.)

[teallarson]

Wasn't sure on testing here. It looks like App Options aren't widely tested. In the UI, if someone puts in a bogus region code, the worst that happens is it returns "0 tables found", same as if they enter a bogus dataset name.

[teallarson]

We decided to not move forward with making the option required with a default as it caused unwanted side effects and BigQuery uses US as a default already. I reset the commit where we tried it out.