Localize more dates and texts (#341)

* Localize more dates and texts

* Adapt source language to 4-letter code for VS code

* Make page titles more reactive to language change

* Translate missing text + fix missed refactoring

* Fix missed page titles refactoring

* Translate nutrition view

* Translate Image upload vue

* Fix default text being defined twice in upload btn

frontend/src/components/MealPlan/ShoppingListDialog.vue

@@ -3,10 +3,10 @@
     <v-dialog v-model="dialog" width="650">
       <v-card>
         <v-card-title class="headline">
-          Shopping List
+          {{$t('meal-plan.shopping-list')}}
           <v-spacer></v-spacer>
           <v-btn text color="accent" @click="group = !group">
-            Group (Beta)
+            {{$t('meal-plan.group')}}
           </v-btn>
         </v-card-title>
         <v-divider></v-divider>