Crowdin integration (#319)

* Fix portuguese localization files

* Use 4-letter code for locales ID

* Update Crowdin configuration file

* Make vuetify locales match with new VueI18n standard

* Fix old locale ID default setting

* Hide project hierarchy from Crowdin

* add dateTimeFormats to Crowdin

frontend/src/locales/dateTimeFormats/pt-PT.json

@@ -0,0 +1,7 @@
+{
+  "short": {
+     "month": "short",
+     "day": "numeric",
+     "weekday": "long"
+  }
+}