[Feat.] OBS: bucket storage class enable for eu-ch

[artem-lifshits]

Summary of the Pull Request

Enable storage class data for bucket in eu-ch region.

PR Checklist

• Refers to: OBS SwissCloud - storage_class is ignored when creating bucket #3225
• Tests added/passed.
• Documentation updated.
• Schema updated.
• Release notes added.

Acceptance Steps Performed

=== RUN   TestAccObsBucket_basic
=== PAUSE TestAccObsBucket_basic
=== CONT  TestAccObsBucket_basic
--- PASS: TestAccObsBucket_basic (79.79s)
PASS

Process finished with the exit code 0

=== RUN   TestAccObsBucket_tags
=== PAUSE TestAccObsBucket_tags
=== CONT  TestAccObsBucket_tags
--- PASS: TestAccObsBucket_tags (22.78s)
PASS

Process finished with the exit code 0

=== RUN   TestAccObsBucket_versioning
=== PAUSE TestAccObsBucket_versioning
=== CONT  TestAccObsBucket_versioning
--- PASS: TestAccObsBucket_versioning (42.08s)
PASS

Process finished with the exit code 0

[otc-zuul]

Build succeeded.
https://zuul.otc-service.com/t/eco/buildset/180c2422ad25441a85c13ba5e802f209

✔️ build-otc-releasenotes SUCCESS in 4m 13s
✔️ noop SUCCESS in 0s
✔️ otc-golangci-lint SUCCESS in 3m 26s
✔️ golang-make-test SUCCESS in 3m 12s
✔️ golang-make-vet SUCCESS in 2m 21s
✔️ tflint SUCCESS in 1m 37s
✔️ goreleaser-build SUCCESS in 8m 41s