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/views/Group/Group.vue

@@ -546,8 +546,6 @@ export default class Group extends mixins(GroupMixin) {
 }
 </script>
 <style lang="scss" scoped>
-@import "../../variables.scss";
-
 div.container {
   background: white;
   margin-bottom: 3rem;

js/src/views/Group/MyGroups.vue

@@ -120,8 +120,6 @@ export default class MyEvents extends Vue {
 
 <!-- Add "scoped" attribute to limit CSS to this component only -->
 <style lang="scss" scoped>
-@import "../../variables";
-
 main > .container {
   background: $white;
 }