Package.extract_file can extract the whole package

Extract_file now takes an optional extract path which defaults to a
temp directory, and omitting the relative path extracts the whole
package.
Cleanup fixes

Misc fixes: rename PACKAGE_TYPE_[EXTRACTABLE|DELETABLE] to
PACKAGE_TYPE_CAN_[EXTRACT|DELETE] to make easier to extend with other
categories.  Import locations.forms module, instead of each form
separately, so it is easier to add new forms, similarly for models in
forms.py
Add misc attributes to Packages

Package has JSONField that stores misc attributes than need to be tracked,
but are not common enough to deserve their own fields.
Add reingest button and endpoint

refs #6488

Add endpoint and button to Packages list for re-ingest. Reingest form
added so user can select which pipeline to reingest on as well as the
type of reingest.
Implement reingest start

refs #6489

Fill out the stub of reingest on the Package model. Reingest copies the
package to SS internal location, extracts it if it's a file, copies a
subset of files to the pipeline's currently processing location, then
deletes the temporary copy.  The METS is always a required file, and all
objects (preservation and original) are required for access reingest.
We only create access copies from originals now, but will from
preservation in the future.