Provide separate completion reports for each DOAJ user class

[richard-jones]

Have a separate report for each user class, and count a user in every report which is relevant to them. So, a user may be in the "admin" sheet for 200 completions, and in the "editor" sheet for 20 completions, and in the "associate editor" sheet for 2 completions.

See also #1385 and #1379

[dommitchell]

... and #1378 and #544