Create a simpler email template for a single incoming file

[mhidas]

The current notification email template is designed around the idea that an incoming file resolves to several individual data files to be handled. In the simplest case where the incoming file is itself the file to be published, this is a bit overkill, and the template could be simpler. Also if the file fails any compliance checks, the checker report could just be appended to the bottom of the email itself, rather than attached in a zip file, saving the recipient a couple of unnecessary steps just to see the report.