New: support xml-style errors from API Allows to see more details about what's going wrong with the request(Azure SAS errors are xml) Tests: got the SAS error locally, saw the logs in ServerManager Bugfix: don't use a closed stream when retrying backup uploading If we fail the upload at the point of consuming the stream (so passed backupBegin), it will close the stream and fall over on Position call, making retries useless. Tests: when running own server it was erroring out on retries with stream closed exception - not anymore. Bugfix: Don't wait after last upload retry Tests: Saw the uploads fail, didn't see the log after last attempt. Update: renamed file back to BackupData I shouldn't have renamed it in the first place. Clean: removing obsolete property Tests: local run was able to upload files