Add logging of outbound payloads to the Payload model

Outbound payloads can now also be logged by toggling the relevant preference in the admin.
When enabled, all outbound payloads will be saved for debugging purposes in the "Payloads"
model and available via the admin.
3 jobs for log-outbound-payloads in 15 minutes and 10 seconds (queued for 1 second)
Status Job ID Name Coverage
  Lint
passed #7683
lint

00:03:14

 
  Test Backend
passed #7684
test_backend

00:07:42

 
  Test Frontend
passed #7685
test_frontend_unit

00:04:12