Refactor user authentication to a more generic strategy

[tramuntanal]

ctws/app/auth/ctws/authenticate_user.rb

Line 27 in 5e91d64

authenticated = user.try(:authenticate, password) || user.try(:valid_password?, password)

In an initializer in the app:

Ctws.user_authentication_callback= ->(login, pwd) {
   session= UserSession.new(login, pwd)
   if session.save!
     session.model
   end
}

then, in AuthenticateUser, check if the callback is setted and

if Ctws.user_authentication_callback.
  Ctws.user_authentication_callback.call(email, password)
else
  user = Ctws.user_class.find_by(email: email)
  authenticated = true
  user
end