Create large file attachment upload session

Create an upload session that allows an app to iteratively upload ranges of a file, so as to attach the file to the specified message. Use this approach to attach a file if the file size is between 3 MB and 150 MB. To attach a file smaller than 3 MB, do a POST on the attachments navigation property instead. As part of the response, this action returns an upload URL that you can use in subsequent sequential PUT queries.