Export StorageType from `@nats-io/obj`

[nounder]

Proposed change

Export StorageType found in @nats-io/jetstream in @nats-io/obj

Use case

Creating a bucket with custom storage uses (objm.create("myobj", { storage: StorageType.File })) enum from jetstream requiring user to individually add both obj and jetstream packages to pkg manager.

Contribution

With pleasure. Is this a change core contributors would be interested in reviwing?