Improve build times

* Fix bulma/buefy being imported many (many !!!) times

* Remove javascript-time-ago because date-fns pretty much does the same
thing

* Make sure languages are loaded asynchronously

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/Settings/SettingMenuItem.vue

@@ -30,8 +30,6 @@ export default class SettingMenuItem extends Vue {
 </script>
 
 <style lang="scss" scoped>
-@import "@/variables.scss";
-
 li.setting-menu-item {
   font-size: 1.05rem;
   background-color: #fff1de;

js/src/components/Settings/SettingMenuSection.vue

@@ -37,8 +37,6 @@ export default class SettingMenuSection extends Vue {
 </script>
 
 <style lang="scss" scoped>
-@import "@/variables.scss";
-
 li {
   font-size: 1.3rem;
   background-color: $secondary;