Rework Notifications: separate and bundle to an amount of 4 (#13300)

* WIP notifications only show 2 at once

* separate and bundle notifications to pairs

* notification fadein/-out/move animations - remove notifications on an interval instead of calculated timeouts

* easier way to import all sprite css files

* add stories + fix sizes / paddings + click to hide + animation fixes

* keep notification at the top but always under the toolbars

* change animations to ease-in 0.25s + add prop to change the delay between deletion and add

* fix adding logic in a rare case of added notifications when only one item is currently visible + add debug mode

* disable lint for notification console

* add more notification example trigger buttons

* potential fix of animation / queue

* increase amount of notifications to 4

* fix sanity

* fix test:unit call again

* new notification styles - fix animations

* keep error notifications visible until manually removed + refactor adding/removal logic

* fix margins

* prevent multiple filling + different delay on filling

* stop and restart removal timer on new notifications

* reduce line-height / apply different margin for icons

* move sprites.scss out and use it in app.vue as well

* update sprites back to 31

website/common/script/index.js

@@ -91,6 +91,7 @@ import updateTask from './ops/updateTask';
 import * as statHelpers from './statHelpers';
 import { unEquipByType } from './ops/unequip';
 import getOfficialPinnedItems from './libs/getOfficialPinnedItems';
+import { sleepAsync } from './libs/sleepAsync';
 
 const api = {};
 api.content = content;
@@ -149,6 +150,7 @@ api.onboarding = onboarding;
 api.setDebuffPotionItems = setDebuffPotionItems;
 api.getDebuffPotionItems = getDebuffPotionItems;
 api.getOfficialPinnedItems = getOfficialPinnedItems;
+api.sleepAsync = sleepAsync;
 
 api.fns = {
   autoAllocate,