Clinical image-based procedures, distributed and collaborative learning, artificial intelligence for combating covid-19 and secure and privacy-preserving machine learning: 10th workshop, clip 2021, second workshop, dcl 2021, first workshop, ll-covid19 2021, and first workshop and tutorial, ppml 2021, held in conjunction with miccai 2021, strasbourg, france, september 27 and october 1, 2021, proceedings