Accessions with large number of transfers can cause timeout

[helrond]

Describe the bug

Accessions with a large number of transfers can cause a timeout.

To reproduce

Steps to reproduce the behavior:

1. Create an accession with a large number (~100) of transfers
2. Observe timeout

Expected behavior

Creating accessions should not cause a timeout.

Impact on your work

When this happens it makes a bit of a mess that has to be cleaned up manually. It's not the end of the world but it's annoying.

Additional context

There is a lot of processing of transfers and rights statements that happens in the view, which is probably what is causing this timeout. Consider other ways of implementing this logic, including as a cron or post-save signal.