GUI: add multi monitors support

Multi monitors support requires a real windows for moving between monitors, but xmage GUI uses single app window/frame for all GUI elements. So it’s impossible with current GUI (java’s swing library).

Possible solution: duplicate and detach some panels into independent windows (simple use case - duplicate whole game panel with all elements, so user can move it into another monitor and setup as it wants, e.g. olen some panels with additional info/zones).

Start by locating the Java Swing GUI code that creates the single application window or frame, then trace how the game panel and other GUI elements are attached to it. Review the existing window structure before evaluating detachable or duplicated panels. Done means the GUI can place relevant content in independent windows that users can move between monitors.

Written by the indexing model from the issue text.