Pass Region For Namespace S3

[shirady]

Explain the changes

1. Pass region for namespace s3 (not using it yet).
   Note: It's something I missed in PR Add Region to Connection Schemas + Use Region in Check Connection #7433 - here we check that it passed to namespace s3.

Issues: Fixed #xxx / Gap #xxx

1. none

Testing Instructions:

1. Deploy noobaa on MInikube or Rancher Desktop (see guide).
   Note: nb is an alias that runs the local operator from build/_output/bin (alias created by devenv).
2. Create namespacestore and pass the region explicitly:
   nb namespacestore create aws-s3 <namespace-store-name> --region=<target-bucket-region>.
3. Create bucket class:
   nb bucketclass create namespace-bucketclass single <bucket-class-name> --resource=<namespace-store-name>
4. Create OBC:
   nb obc create <obc-name> --bucketclass=<bucket-class-name>
5. Use the alias from previous step and run s3 operation, for example:
   kubectl port-forward -n default service/s3 12443:443
alias s3-user-1='AWS_SECRET_ACCESS_KEY=<paste-here> AWS_ACCESS_KEY_ID=<paste-here> aws --no-verify-ssl --endpoint-url https://localhost:12443'
s3-user-1 s3api head-object --bucket <bucket-name> --key <key-name>
6. After adding printings to _setup_single_namespace (print r.region) see that the region passed.

• Doc added/updated
• Tests added