Internationalize Active Record Errors

[sylvieed]

From #1820, helps #3165

Whether or not errors are correctly localized is weirdly inconsistent. A couple of examples:

• With a bad transcription markup, there is no translation other than English.

• With a work or collection title that's too short, half of the translation is localized.

• With an invalid login, the other half of the translation is localized. I think this is because of our Devise locales.

There is a chance that the errors prohibited this... is something that happens when ActiveRecord tries to save a model and fails to find a (very specific) key in a message catalog for the model.

See the first (or best) answer here: https://stackoverflow.com/questions/20676111/rails-i18n-not-working-for-header-error

(Note that that would not explain the five places where we are actually using a ...prohibited this... string literal in the views.)