Add support for new languages (#781)

* Add support for Slovak language

* Add support for new languages

Catalan, Danish, Norwegian and Russian

frontend/src/plugins/vuetify.js

@@ -3,6 +3,7 @@ import Vuetify from "vuetify/lib";
 
 Vue.use(Vuetify);
 
+import ca from "vuetify/es5/locale/ca";
 import de from "vuetify/es5/locale/de";
 import en from "vuetify/es5/locale/en";
 import es from "vuetify/es5/locale/es";
@@ -10,7 +11,10 @@ import fr from "vuetify/es5/locale/fr";
 import hu from "vuetify/es5/locale/hu";
 import it from "vuetify/es5/locale/it";
 import nl from "vuetify/es5/locale/nl";
+import no from "vuetify/es5/locale/no";
 import pl from "vuetify/es5/locale/pl";
+import ru from "vuetify/es5/locale/ru";
+import sk from "vuetify/es5/locale/sk";
 import sv from "vuetify/es5/locale/sv";
 import zhHans from "vuetify/es5/locale/zh-Hans";
 import zhHant from "vuetify/es5/locale/zh-Hant";
@@ -43,6 +47,8 @@ const vuetify = new Vuetify({
   },
   lang: {
     locales: {
+      "ca-ES": ca,
+      "da-DK": en, // language not supported by Vuetify
       "de-DE": de,
       "en-US": en,
       "en-GB": en,
@@ -51,7 +57,10 @@ const vuetify = new Vuetify({
       "hu-HU": hu,
       "it-IT": it,
       "nl-NL": nl,
+      "no-NO": no,
       "pl-PL": pl,
+      "ru-RU": ru,
+      "sk-SK": sk,
       "sv-SE": sv,
       "zh-CN": zhHans,
       "zh-TW": zhHant,

frontend/src/store/modules/language.js

@@ -9,6 +9,14 @@ const state = {
       name: "British English",
       value: "en-GB",
     },
+    {
+      name: "Català (Catalan)",
+      value: "ca-ES",
+    },
+    {
+      name: "Dansk (Danish)",
+      value: "da-DK",
+    },
     {
       name: "Deutsch (German)",
       value: "de-DE",
@@ -29,6 +37,10 @@ const state = {
       name: "Italiano (Italian)",
       value: "it-IT",
     },
+    {
+      name: "Norsk (Norwegian)",
+      value: "no-NO",
+    },
     {
       name: "Nederlands (Dutch)",
       value: "nl-NL",
@@ -37,6 +49,14 @@ const state = {
       name: "Polski (Polish)",
       value: "pl-PL",
     },
+    {
+      name: "Pусский (Russian)",
+      value: "ru-RU",
+    },
+    {
+      name: "Slovenčina (Slovak)",
+      value: "sk-SK",
+    },
     {
       name: "Svenska (Swedish)",
       value: "sv-SE",