Fix otherwise break existing translations

This fix is to make **existing angular-translate** translations still work. Because I already use it with my own JSON files for translations. By separating this dialog translation config into a separate module **'dialogs.default-translations'** will make it possible for us to optionally include the default translations.

If we already use our own, we can just add all the keys to our own JSON file (like 'DIALOGS_ERROR', 'DIALOGS_ERROR_MSG', etc).

Otherwise to use the defaults we just add module 'dialogs.default-translations'.