Delete submission creation event(NEW SUBMISSION) on submission deletion (#3445)

Possible Fix of #3442 

On submission deletion, all other activities, determination, and other
things are getting removed but as this `NEW SUBMISSION` event is not
directly connected to submission so not getting removed. It is creating
issues at the time of user deletion even after submission deletion.

I was also thinking to show the model name, and object name in error
itself but user deletion only seems to be dependent on `Activities` and
`Events`(user can also be deleted only by removing Activities and events
not submissions related to them), and even if we show staff the event or
activities ids I don't think staff can easily delete those anyhow via
UI. I think we need to decide a better way to delete a user, maybe issue
#3441 help us?