Nuke 9.6.0

• Add ImageRequest.CachePolicy.returnCacheDataDontLoad, #456
• Add ImagePublisher (Combine extensions)
• Add a convenience dataLoadingError property to ImagePipeline.Error
• Remove APIs deprecated in versions 9.0-9.1
• Add a note on waitsForConnectivity in Nuke Docs
• Add "Low Data Mode" in Nuke Docs