Testing | Sample exception + permission | Check response headers and problem code

[shivanshs9]

Code a sample view which uses permissions derived from BaseProblemPermission class and throws a registered exception. Write tests with this view to test the following behaviors:

• When the permission passes, content type is "application/json".
• When the permission fails, content type is "application/problem+json" and the problem code is the same as the one declared in the registered exception with the permission.