Laziness of RequestHandler.current_user

The RequestHandler.current_user getter defers the evaluation of RequestHandler.get_current_user until it's needed. However, when either RequestHandler.get_template_namespace or UIModule.init is called, the current_user getter is called, and get_current_user is evaluated. This should be avoided, since the current request might not need the current user at all, and get_current_user might be expensive to evaluate.

Start by tracing the RequestHandler.current_user getter and its interactions with RequestHandler.get_template_namespace and UIModule.init. Verify where get_current_user is evaluated during template namespace and UI module setup. Done means those paths preserve lazy evaluation and only evaluate the current user when the getter is actually needed.