Tasks: Improve user awareness of tasks that are waiting for user input #19321

Summary

When running a task, it mights require some additional user input to run. When this happen, the user should be notified and be aware of this so they could take action to continue with the task.

Acceptance Criteria

• When a task changes the state to "idle" the user should be notified and see it in the notification widget in the navbar
• The "task" navigation item should display the number of idle tasks
• The tasks, in the tasks page, should add a tab option to filter idle tasks

Designs

Notification

Navbar badge

Idle tab

Technical details

• Since we don't have paginated results for tasks, we can filter and count using the tasks endpoint.