Display error message on copy creation

This addresses displaying a decent message to the user if the copy creation fails due to duplicate COPY role.

Some points to consider:
* I added a "flashError" to url interceptor. This is to enable the all errors to be displayed even if the user is redirected to another page. 
* I now redirect the user back to the Work screen on the failure. I originally redisplayed the copy create screen but this resulted in overwriting one of the existing copies. So the user can get the message and click back to the copy screen with their values. 

Not a great solution but better than the previous error screen.