Refactor `updateDisplay` method from `ZettelkastenView` to a new Controller

[RalfBarkow]

The updateDisplay method in ZettelkastenView is currently responsible for updating various display components. However, this responsibility better aligns with the Controller in the Model-View-Controller (MVC) pattern. Therefore, we need to refactor this method from ZettelkastenView to a new Controller class.

Task Checklist:

• [ ] Create a new Controller class.
• [ ] Move the updateDisplay method from ZettelkastenView to Controller.
• [ ] Modify ZettelkastenView to delegate updateDisplay calls to the Controller.
• [ ] Update any relevant documentation or comments.
• [ ] Test the application to ensure the refactoring hasn't introduced any regressions.

Summary

This issue will help track the refactoring process and ensure that the updateDisplay method is properly moved to the appropriate class in alignment with the MVC pattern.

[github-actions[bot]]

This issue is stale because it has been open for 30 days with no activity.

[github-actions[bot]]

This issue was closed because it has been inactive for 14 days since being marked as stale.