Updating twig-gettext extractor (and possibly changes for translating Finnish, Swedish and English UI)

[joelit]

The Poedit used for syncing the translation UI templates is used with twig-gettext-extractor tool.

• Package twig/extensions is abandoned, you should avoid using it. No replacement was suggested. nat-lib-fi/skosmos dev-master requires twig/extensions (1.5.*)
  umpirsky/twig-gettext-extractor v1.3.1 requires twig/extensions (~1.0)

There are several branches available for twig-gettext-extractor, but none have been updated recently. If we want to drop this dependecy, we should consider the current setup of Poedit or whether we can continue updating the translation templates manually without Poedit.

[joelit]

Both twig/extensions and umpirsky/twig-gettext-extractor are abandoned packages. Removing the first, as it's only used by Poedit.