*: Create Django 3.2 ports for net-mgmt/netbox

• Django 2.2 is currently the "default" version in the ports tree due its long term support until April 2022. Thus ports that are assigned to that version will exist until then.
  
  The following ports are required to make the upgrade of net-mgmt/netbox to the 2.11 release possible because it requires Django 3.2. All of the ports listed below were created on the basis of their respective original ports:
  • devel/py-dj32-django-rq
  • www/py-dj32-django-auth-ldap
  • www/py-dj32-django-cacheops (updated to a newer release)
  • www/py-dj32-django-cors-headers
  • www/py-dj32-django-debug-toolbar
  • www/py-dj32-django-filter
  • www/py-dj32-django-js-asset
  • www/py-dj32-django-mptt
  • www/py-dj32-django-prometheus
  • www/py-dj32-django-redis
  • www/py-dj32-django-tables2 (updated to a newer release)
  • www/py-dj32-django-taggit (updated to a newer release)
  • www/py-dj32-django-timezone-field
  • www/py-dj32-djangorestframework
  • www/py-dj32-drf-yasg

• Add/update the related CONFLICTS_INSTALL entries as well.

Reviewed by: koobs, sunpoet
Differential Revision: https://reviews.freebsd.org/D30977