New Features

• SignedUploader component for handling the workflow associated with signed urls on aws and google cloud

• If no fields are set, and props.request.fileName is empty, files will be uploaded without formdata. This is needed for google cloud and aws's signed urls

Breaking

• Not passing fileName does not use form data, so the file is uploaded without it. Set fileName:"file" in the request object for it to use formdata.
• Removed triggerProgress and returning a promise to onComplete in favor of SignedUpload for that purpose.
• canceled value is now aborted inside of the children for Uploader and SignedUploader
• failed is now just error which contains the actual error that happened
• progress is now a key in the object passed to the imperative api function.