Auto-detect the AWS region for the S3 bucket for Textract and use that region

[jonfritz]

Is your feature request related to a problem? Please describe.
Right now, you need to hardcode the AWS region for Textract. The job will fail if you hardcode a different region than the specified S3 bucket.

Describe the solution you'd like
It would be nice to have it default to auto-detecting the region where the S3 bucket for Textract is, and then use Textract in that region.

Describe alternatives you've considered
N/A

Additional context
The demo script for the Quickstart requires US-East-1, and it could use other regions if this feature existed.

[bsowell]

Oh weird. I was not aware that Textract doesn't support cross-region calls.