* Update webpack-config to more closely align with SilverStripe core modules
* Automated linting
* Remove all JS linting errors, use let/const for assignment, do not reassign callback arguments
* Rebuild dist files, remove yarn lock from build command, remove source map files
All bulk handlers and the bulk uploader now use a common HTTPBulkToolsResponse to return a common json format and handle errors. The front end uses this json to update the drifield accordingling.
Now using the SilverStripe webpack-config which lets us extend the CMS front end components. Allowed to write a quick hack fixing the add-from-file for bulk uploader
