💫 Animated collapsible sidebar

lib/translations/en_us.dart

@@ -383,4 +383,6 @@ const i18nEnglish = {
       'Since the App has entered the background, there may be a time difference between the message list and the server. Click to Refresh.',
   'messageHistoryWipe': 'Wipe local message history',
   'unknown': 'Unknown',
+  'collapse': 'Collapse',
+  'expand': 'Expand',
 };

lib/translations/zh_cn.dart

@@ -353,4 +353,6 @@ const i18nSimplifiedChinese = {
   'messageOutOfSyncCaption': '由于 App 进入后台，消息列表可能与服务器存在时差，点击刷新。',
   'messageHistoryWipe': '清除消息记录',
   'unknown': '未知',
+  'collapse': '折叠',
+  'expand': '展开',
 };