LibreCAD Properties Widget and entities mass-editing

This is demo for Properties Widget for LibreCAD 2.2.2-alpha. The Properties widget is a powerful new tool for inspecting and bulk-editing selected entities. Beyond standard editing, it acts as a dynamic control hub by integrating context-aware commands and centralizing various interface settings. It improves performance by reducing cognitive load, eliminating redundant clicks, and providing a clean, adaptive interface that scales with the complexity of the project.