Viewer: Add a three-dot menu to perform additional actions that otherwise wouldn't fit on the screen

**As a user, I would like to have additional options/actions available in the viewer through a three-dot menu, so that I am not limited by my screen size or orientation.**

This is a screenshot of the development build with the new action menu on the right and the close button on the left:

![Image](https://github.com/user-attachments/assets/1a66fff6-a02b-4c4c-809f-0c62cae5c269)