Include aws region in dataset information for AWS Seismic DDMS data
When using sdapi to retreive seismic ddms data coming from AWS, a user needs to first set the AWS_REGION environment variable (see ticket seismic-store-cpp-lib#21 (closed)).
To better handle this use case, the get dataset service /dataset/tenant/{tenantid}/subproject/{subproject}/dataset/{datasetid}
should provide information regarding the aws region if the dataset is stored in s3 storage.