[Widget Editor] Add close all option on the opened widget editor tabs

<img width="776" height="154" alt="Image" src="https://github.com/user-attachments/assets/d3d093de-6c70-485a-a85e-3859c4c042a6" />


vgl. global editors

<img width="226" height="157" alt="Image" src="https://github.com/user-attachments/assets/007be2ec-5d9b-44d8-868b-b3ca0b90ee08" />


make that global available to all configuration screens. 