Fix broken translator in PHP 8.0;  for some reason it's pulling in v3 of the translation-contracts instead of v2.x

updated twig to version 3 and added wrapper for translation via symfony/twig-bridge

Co-authored-by: Ulrik nielsen <un@ipwsystems.dk>

Add missing sqlite3 extension to require-dev as it is needed for the unit tests.

Memcache server always seen as down when using moxi

Now also considers any attributes.po in the configured theme, if any.
Makes the attributes.extradictionary config setting obsolete.