Pretty Submission Report Email and Fix Exception Handling

[BenGalewsky]

Problem(s)

1. The confirmation email that is sent to the submitter is very plain and doesn't contain information people need
2. The exception workflow was not working
3. At some point the mkdir action provider stopped creating parent dirs as needed

Approach

This is not an ideal PR since so many things are wrapped up together.

Confirmation Email

In order to preview and debug the HTML, I put the template in a separate html file. The Flow script reads that file and includes in the flow definition.

The email includes a block that contains the citiation. This required generating string containing all of the author names. This is not possible as a flow expression so I added a new flow variable which keeps this handy.

Create SourceID directory

The files in the repo are kept in a subdirectory of a directory named after the submission's source ID. The subdirectory is for the version. Previously, the mkdir ActionProvider would create the entire path as needed. This stopped working recently. I added a new flow variable for the sourceID path and call mkdir on this first (telling it to ignore any errors from existing dirs) and then create the version subdirectory.

Exception Handling

The flow was swallowing errors. I turned that off and tried to use the exception handler to send out an email. This was failing due to missing input parameters and some expression formatting mistakes in the flow

[blaiszik]

Looks great, thanks for adding and updating tests as well.