Add user-specified manual normalization event details

refs #5216

Add a form to enter event detail information for manually normalized files
after Normalization takes place.  Only works for files that were normalized
prior to Transfer.

Update normalize.py to add Derivation and Event for manually normalized
files.  Files are left in the manualNormalization directory so that redo
normalization doesn't delete them with Archivematica-generated files.
Update the cleanup script to remove duplicate Events and Derivations. Update
scipt that associates original and manual normalized files to modify an
existing Event, if it can find one.

Add Events & Derivations to models.py.
Add wait point for entering manual normalization metadata

refs #5216

Add a 'user choice' after handling manually normalized files, so the system
pauses until manual normalization event detail information has been
entered. Since this is not a real choice, use set replacement dict with no
real value in replacement dict.
Add preconfigured choice to skip entering manual normalization metadata

refs #5216

Add 'skip waiting to allow manual normalization of metadata entry' to
preconfigured choices, and set the default to yes (skip waiting).
Minor fixes to manual normalization metadata

Update processing config text, fix typo in template, add text for when
there are no manually normalized files detected.