Use app locale with toLocaleString/toLocaleDateString

Fixes inconsistent date formatting when browser language is different
from PleromaFE language.

src/components/chat_message_date/chat_message_date.vue

@@ -5,6 +5,8 @@
 </template>
 
 <script>
+import localeService from 'src/services/locale/locale.service.js'
+
 export default {
   name: 'Timeago',
   props: ['date'],
@@ -16,7 +18,7 @@ export default {
       if (this.date.getTime() === today.getTime()) {
         return this.$t('display_date.today')
       } else {
-        return this.date.toLocaleDateString('en', { day: 'numeric', month: 'long' })
+        return this.date.toLocaleDateString(localeService.internalToBrowserLocale(this.$i18n.locale), { day: 'numeric', month: 'long' })
       }
     }
   }

src/components/settings_modal/tabs/security_tab/security_tab.js

@@ -1,6 +1,7 @@
 import ProgressButton from 'src/components/progress_button/progress_button.vue'
 import Checkbox from 'src/components/checkbox/checkbox.vue'
 import Mfa from './mfa.vue'
+import localeService from 'src/services/locale/locale.service.js'
 
 const SecurityTab = {
   data () {
@@ -37,7 +38,7 @@ const SecurityTab = {
         return {
           id: oauthToken.id,
           appName: oauthToken.app_name,
-          validUntil: new Date(oauthToken.valid_until).toLocaleDateString()
+          validUntil: new Date(oauthToken.valid_until).toLocaleDateString(localeService.internalToBrowserLocale(this.$i18n.locale))
         }
       })
     }

src/components/timeago/timeago.vue

@@ -9,6 +9,7 @@
 
 <script>
 import * as DateUtils from 'src/services/date_utils/date_utils.js'
+import localeService from 'src/services/locale/locale.service.js'
 
 export default {
   name: 'Timeago',
@@ -21,9 +22,10 @@ export default {
   },
   computed: {
     localeDateString () {
+      const browserLocale = localeService.internalToBrowserLocale(this.$i18n.locale)
       return typeof this.time === 'string'
-        ? new Date(Date.parse(this.time)).toLocaleString()
+        ? new Date(Date.parse(this.time)).toLocaleString(browserLocale)
-        : this.time.toLocaleString()
+        : this.time.toLocaleString(browserLocale)
     }
   },
   created () {