Have MemberPresenter return false to undefined methods

In order to use the MemberPresenter more flexibly, I want to remove the constant checking. The Presenter should be able to intialise with a `nil` object and then deal with the consequences of that. This approach will return `false` to any method not defined on the presenter or the presented object.

Signed-off-by: jonathan.kerr <3410350+jonodrew@users.noreply.github.com>

Author: jonodrew

app/presenters/member_presenter.rb

@@ -1,4 +1,5 @@
 class MemberPresenter < BasePresenter
+  include FalseResponder
 
   def initialize(current_user)
     @member = current_user

app/services/false_responder.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module FalseResponder
+  def method_missing(method_name, *args, &block)
+    false
+  end
+
+  def respond_to_missing?(method_name, include_private = false)
+    true
+  end
+end