Update json dumper
Some fixes for DumpEventDataToJSON
(which is not run in production).
I removed the old-style configuration, fixed the new, and added a new way to dump a dummy file for calibration.
Please note there is still an issue with the configuration, because the EventCnvSuperTool seems misconfigured. I'm pretty sure I know what the fix is, but since this was really about the dummy file, I don't care for now.