Provide a way to delete submitted internal form on a request/ticket

Issue Summary

Once an internal form is submitted, there'll be no option to delete it.

Steps to Reproduce

1. In Request View, add a form
   1. Make sure the form is internal (yellow)
2. Edit and submit the form
3. There will now be no delete action in the meatball menu

Expected Results

There should be a way to delete internal form.

Actual Results

There is no option to delete internal form.

Workaround

1. In meatball menu
2. Click 'Make form external'
3. Click 'Open customer edits'
4. Click 'Delete form'