Pinned statuses (#4675)

* Pinned statuses

* yarn manage:translations

app/javascript/mastodon/locales/zh-CN.json

@@ -168,6 +168,7 @@
   "status.mention": "提及 @{name}",
   "status.mute_conversation": "Mute conversation",
   "status.open": "展开嘟文",
+  "status.pin": "Pin on profile",
   "status.reblog": "转嘟",
   "status.reblogged_by": "{name} 转嘟",
   "status.reply": "回应",
@@ -179,6 +180,7 @@
   "status.show_less": "减少显示",
   "status.show_more": "显示更多",
   "status.unmute_conversation": "Unmute conversation",
+  "status.unpin": "Unpin from profile",
   "tabs_bar.compose": "撰写",
   "tabs_bar.federated_timeline": "跨站",
   "tabs_bar.home": "主页",