[Feature Request] Management command that schedules a gencache.

[ILW8]

Is your feature request related to a problem? Please describe.
With the migration away from cron for running gencache, manually updating gencache outside of the predefined schedule has become significantly more involved.

Describe the solution you'd like
Add a management command that creates a one-off celery task.

[greenfrogs]

Implemented and deployed but need testing.