add Storage.upload(Path)

[dmitry-fa]

In addition to Blob.uploadFrom() methods which require a Blob instance to be created first there should be a way to upload a resource to the storage without creating an instance of Blob:

interface Storage {
    void upload(BlobInfo blobInfo, Path path, BlobWriteOption... options);
    void upload(BlobInfo blobInfo, InputStream content, BlobWriteOption... options);
}

Implementing this feature means extending of public interface.

[dmitry-fa]

Extension the Storage interface is incompatible change. Such a minor feature as adding helper upload methods should not break compatibility. Instead of extending the main interface it's better to introduce a new class like StorageUtilities and put various helpers there.