Fix #543: Always show logged-in user's full name or username in page …

[seav]

Proposed changes in this pull request

• Fix User name in header bug #543:
  • Bug root cause: the OrganizationMembersEdit view is a subclass of the generic DetailView and it views a single User object, namely the organization member whose permissions are being edited or to be removed from the organization. The default behavior of DetailView is to helpfully add a context variable whose name is the model_name of the object model (documentation). Thus, the user currently being viewed gets placed into the user context, which overrides the logged-in user leading to the bug.
    • This issue trips up a lot of Django projects so the documentation was updated with a special note describing the issue.
  • Override DetailView's get_context_object_name() method to avoid overwriting the logged-in user.
  • Modify an existing unit test to catch this bug and to confirm it has been fixed.

When should this PR be merged

Anytime.

Risks

None.

Follow up actions

None.