UI: Menu items can be cut off / unreachable in small windows

## Summary
Version: 2.3.4

Operating System: All

What is happening: Ping Viewer menus have a fixed size, and do not support scrolling when the window is smaller than the menu, which can cut off menu items. This is particularly problematic on small screens (where some menu items may be completely inaccessible), or when users want a small Ping Viewer window to sit on top of their vehicle's GCS.

How to reproduce it: Open PingViewer, open a menu, resize the application to be smaller than the menu, fail to access the now hidden items.

## Additional information

Start by reproducing the issue in PingViewer 2.3.4: resize the application smaller than an open menu and verify that some items cannot be reached. Locate the desktop menu layout and sizing code, then confirm that all menu items remain accessible in a small window through scrolling or equivalent behavior.

Written by the indexing model from the issue text.