Summary
Investigate if there are industry-standard conventions to specify a bucket along with a region for S3.

Motivation
We want to change the S3 code to accept bucket configuration in that convention. We will also like to document the changes for the users to follow.

At the moment the S3 extension accepts the bucket configuration in the following form:

"bucket-name;region"

For more details here is a review comment that talks more about the issue.

• Does this affect any team outside of WT?
  Not yet, but eventually serverless will be a consumer for S3 extension

• Is this issue urgent?
  No

Acceptance Criteria (Definition of Done)
We have investigated the conventions and decided how to provide the bucket and region for the S3 extension, and made relevant code and test changes. Also update the documentation to reflect the changes.

• Testing
  Existing tiered storage tests with S3 scenario are sufficient.

• Documentation update
  Yes, documentation for the S3 extension (and possibly the architecture guide, WT-8135)