#1357 Cleanup report to find invalid uses of the Narrator template

[Ahasuerus]

Create a new cleanup report to find invalid uses of the Narrator template in Publication notes. An Advanced Search report on "Notes contains {{narrator" AND "Format does not contain audio" finds matching 7 pubs. In certain cases this permutation can be valid, e.g. when the pub consists of a paper book as well as its audio version. Other times it's a side effect of a cloning submission. The new cleanup report needs to look for these two conditions and let moderators "ignore" valid occurrences.

[Ahasuerus]

Implemented in:

edit/cleanup_lib.py
edit/cleanup_report.py
nightly/nightly_job.py

Installed in SVN 542 on 2020-06-11. Closing the FR.