Azure Storage blob - Get Blob Properties method

Hi! Thanks for all the hard work on this SDK so far, it's been great to work with.

It looks like the [Get Blob Properties](https://docs.microsoft.com/en-us/rest/api/storageservices/get-blob-properties) method is missing from the `Blob` trait. Is there a reason it's missing, or would you be willing to accept a PR to add it?