feat: Move language option to profile setting (#387)

frontend/messages/zh-CN.json

@@ -101,6 +101,7 @@
     "confirm_password": "确认密码",
     "invalid_email": "无效的邮箱地址",
     "invalid_password": "密码必须至少包含 8 个字符",
+    "invalid_locale": "无效的语言",
     "username_empty": "用户名不能为空",
     "password_empty": "密码不能为空",
     "password_not_match": "密码不匹配",
@@ -125,6 +126,9 @@
     "confirm_new_password": "确认新密码",
     "update_password": "更新密码",
     "password_updated": "密码更新成功",
+    "change_locale": "修改语言",
+    "update_locale": "更新语言",
+    "locale_updated": "语言更新成功",
     "change_avatar": "修改头像",
     "upload_avatar": "上传头像",
     "remove_avatar": "移除头像",