Add WasbIO / WasbFileSystem (Azure Blob Storage)

Azure Blob Storage can be accessed by using the wasb:// and wasbs:// protocols. This should be quite similar to the hdfs:// implementations already there.

We should just be able to use it like this:

        (
            p
            | ReadFromText("yourcontainer@youraccount.blob.core.windows.net/test/sample.txt")
            | WriteToText("output.txt", shard_name_template="", num_shards=0)
        )

See:

 [1] https://docs.microsoft.com/en-us/azure/hdinsight/hdinsight-hadoop-use-blob-storage

 [2] https://hadoop.apache.org/docs/current/hadoop-azure/index.html

 [3] https://gerardnico.com/azure/wasb