Opt: Improve code

- Delete unnecessary import
- Rename Alas to AlasManager
- Move global var/function into class var/method
- Resolve some IDE warning

module/webui/lang.py

@@ -1,6 +1,5 @@
 from typing import Dict
 
-import module.logger  # Change folder
 from module.config.utils import *
 
 LANG = 'zh-CN'