Guild A/B test and Achievement (#8740)

* WIP(guilds): AB test pester modal

* WIP(AB-test): guild pester cont'd

* fix(style): linting error

* fix(AB-test): markModified and notif enum

* fix(tests): update AB expectations

* fix(modal): remove extra includes

* feat(achievements): add Joined Guild cheevo
Also removes unused achievement sprites, and properly saves counter used in A/B testing

* fix(style): linting error from conflict

website/common/script/content/achievements.js

@@ -102,6 +102,11 @@ let basicAchievs = {
     titleKey: 'royallyLoyal',
     textKey: 'royallyLoyalText',
   },
+  joinedGuild: {
+    icon: 'achievement-guild',
+    titleKey: 'joinedGuild',
+    textKey: 'joinedGuildText',
+  },
 };
 Object.assign(achievementsData, basicAchievs);