fix: implement 'login' event for WebContents (#20954)

lib/browser/api/web-contents.js

@@ -423,6 +423,10 @@ WebContents.prototype._init = function () {
     })
   }
 
+  this.on('login', (event, ...args) => {
+    app.emit('login', event, this, ...args)
+  })
+
   const event = process.electronBinding('event').createEmpty()
   app.emit('web-contents-created', event, this)
 }