Many management actions only make sense if a user has been selected
beforehand.
We updated :check_verified_user method to be able to check actions that need to
have a user selected in order to avoid exceptions.
We need this control as :only_verified_user is not restrictive enough. The reason is
that the :managed_user method used in the :only_verified_user if it does not find a
user it does an initializce (find_or_initialize_by). This causes that when we have
"skip_verification" to true, it returns this non-persisted user as "verified".
These changes affect the actions of Account, Budgets and Proposals Controller
when no user is selected.