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/Account/Profile.vue

@@ -144,8 +144,3 @@ export default class Profile extends Vue {
   }
 }
 </script>
-<style lang="scss">
-@import "../../variables";
-@import "~bulma/sass/utilities/_all";
-@import "~bulma/sass/components/dropdown.sass";
-</style>

js/src/views/Account/Register.vue

@@ -168,7 +168,6 @@ export default class Register extends mixins(identityEditionMixin) {
 </script>
 
 <style lang="scss" scoped>
-@import "../../variables.scss";
 .avatar-enter-active {
   transition: opacity 1s ease;
 }