feat:新功能

webshell模块
1.上传功能
2.下载功能（还需要测试，进行中）
3.header顶部菜单分割线及xshell入口角标样式调整

nezha-fronted/src/components/common/language/en.js

@@ -66,6 +66,14 @@ const en = {
   },
   webshell:{
     shellTitle:'Local Shell',
+    upload:'Upload',
+    download:'DownLoad',
+    uploadTitle:'Upload',
+    downloadTitle:'DownLoad',
+    uploadButtonTitle:'Upload',
+    fileSelect:'select',
+    downloadButtonTitle:'Download',
+    filePath:'file path',
   },
   dashboard:{
     title:'Dashboard',