Defining BaseKeyStorageLocation and StsStorageLocation interfaces and adding them to ExternalS3StorageLocation and (Synapse)S3StorageLocation.
Wiring this through the Storage Location, Project Setting, and Upload Destination APIs.
SynapeStorageLocation auto-generates BaseKey when the stsEnabled flag is true.
Can only be added to Folders, not Projects.
StsStorageLocation cannot be added with other StorageLocations.
Can only add/update/delete StsStorageLocation on an empty folder.
Child Folders cannot override StorageLocation.