Issue #377 - Move the copy functionality to run in a task
Fixes issue #377 - Move the copy functionality to run async

* The normal task has a timeout of 10min in a frontend instance
* I tried to execute it in a backend but i was getting some strange
  behavior resetting the status of the survey
* A new `COPYING` status has been added
* When a survey is in status `COPYING` the user can't access access
  it for editing