Layout for edit registration page

[dvanderbeek]

We should use a custom controller here so that the page uses the storytime layout. Otherwise, content from the main_app layout might interfere with the storytime dashboard elements on the edit registration page. It will also fix the issue that requires the main app's ApplicationController to add the engine's helpers.

[eanlain]

This sounds like this was back when Devise was included within Storytime...