Import translations out of the box

Added config translations and po files for NL, FR & DE.

NOTES
- Requires config_import_locate setting to import the config translations for the categories
- Assumes the location of the module (for the import of the po files), as it would be if used with Rocketship

* Updated config translation files
* Removed locale files & info.yml config. Added translations to localize.drupal.org, but they need to be accepted by someone from the French & German language teams.

we recently changed the default categories that ship with the module: ✨ Standardise default categories and category names Fixed
also, there is a new request to change the intro text and button labels to be more in line with GDPR requirements: ✨ New text for the cookie modal & buttons Fixed
it's better to do that first, before re-rolling the changes in this ticket

Rebased on top of 2.1.x, renamed category config files and updated some translations to reflect changes in v2.