Realtime env list

Description

Frontend:

• Adds polling function to environment table
• If any folder was opened while polling, keeps it open and refreshes the content
• Adds polling function to folders table
• Adds missing eventhub to folders table to make request when action is clicked
• Removes unused event

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests
  • Added for this feature/bug
  • All builds are passing

What are the relevant issue numbers?

Fixes gitlab-org/gitlab-ce#31701