Allow users to see their own api_key
Allow users to see their own api_key

This solves an occasional onboarding usability complaint: that it's hard
to find your own API key. Previously you could only find it by viewing
the page source or using the rails console, but it makes sense to
display it here.

API keys for other users remain hidden, regardless of your permissions.

pervino/solidus,pervino/solidus,pervino/solidus,pervino/solidus