missing uri property on Blob()

[yan-hic]

Can be constructed but would help to get the URI natively as a property of Blob() e.g. gs://my_bucket/path/my_blob
This is consistent with instantiating a blob using its URI: my_bucket.from_string(uri)

[holtskinner]

This would be very helpful for a number of different use cases, specifically with other Google Cloud products that require the full gs:// uri