readd provider emiting event

apps/remix-ide/src/app/files/fileManager.js

@@ -140,6 +140,7 @@ class FileManager extends Plugin {
   refresh () {
     const provider = this.fileProviderOf('/')
     // emit rootFolderChanged so that File Explorer reloads the file tree
+    provider.event.emit('rootFolderChanged', provider.workspace || '/')
     this.emit('rootFolderChanged', provider.workspace || '/')
   }