feat: Add Palette Editor for Enhanced Color Management

- Introduced a new PaletteEditorWidget for visual editing of dungeon palettes, allowing users to select and modify colors.
- Integrated palette editor into DungeonEditorV2, enabling real-time updates and re-rendering of rooms upon palette changes.
- Enhanced GUI layout to include a dedicated palette editor card, improving user experience and accessibility.
- Implemented callback functionality to notify when palette changes occur, ensuring seamless integration with room rendering.

src/app/editor/dungeon/dungeon_editor_v2.h

@@ -14,6 +14,7 @@
 #include "app/zelda3/dungeon/room_entrance.h"
 #include "app/gui/editor_layout.h"
 #include "app/gui/widgets/dungeon_object_emulator_preview.h"
+#include "app/gui/widgets/palette_editor_widget.h"
 #include "imgui/imgui.h"
 
 namespace yaze {
@@ -109,6 +110,7 @@ class DungeonEditorV2 : public Editor {
   DungeonCanvasViewer canvas_viewer_;
   DungeonObjectSelector object_selector_;
   gui::DungeonObjectEmulatorPreview object_emulator_preview_;
+  gui::PaletteEditorWidget palette_editor_;
   
   bool is_loaded_ = false;
 };