[keyboard] Move responsibility for retranslation to Config

- only widgets get language change events, so we need to
  hook that up to the ViewSteps and inform the Config
  object so that it can (re)load translations for the
  keyboard data.

src/modules/keyboard/Config.cpp

@@ -560,3 +560,8 @@ Config::setConfigurationMap( const QVariantMap& configurationMap )
         m_writeEtcDefaultKeyboard = true;
     }
 }
+
+void
+Config::retranslate()
+{
+}