JCLOUDS-671: Use Iterable payload slicer for Azure

Payload slicer has a method that returns an iterable of payloads that
works on non-repeatable InputStreams that was introduced to fix
multi-part uploads in Swift (JCLOUDS-356). This commit applies the
same method to fix multi-part uploads for Azure blob store.
JCLOUDS-671: test putBlob with large multi-part InputStream