Function write_non_window_pointer_moved_messages_system 

pub fn write_non_window_pointer_moved_messages_system(
    hovered_non_window_egui_context: Option<Res<'_, HoveredNonWindowEguiContext>>,
    cursor_moved_reader: MessageReader<'_, '_, CursorMoved>,
    egui_input_message_writer: MessageWriter<'_, EguiInputEvent>,
    egui_contexts: Query<'_, '_, (&EguiContextSettings, &EguiContextPointerPosition), With<EguiContext>>,
)

Reads CursorMoved messages and wraps them into EguiInputEvent for a HoveredNonWindowEguiContext context (if one exists).