Errors page single with localization (js version)

[MdreW]

New proposal for errors page.

Use the same errors page for all errors and add more detail and localization with javascript.

For security reason the errors details can't be add from with a simple string, but must be decoded from the error's code.

With a javascript we read a json with all codes and his error details and add this in the error box.

Vantage:

• we an remove jinja from requisites
• We can load the errors messages and other details from simple a json file
• Is simple presonalize the template and the messages
• don't require an asyncronous page generation (like #82)

example json:

en:
  '20':  ''Destination is not valid'
  '30': 'Issuer NameFormat is invalid'
it:
  '20': 'Destinazione di ritorno non valida'
  '30': 'issuer non valido'