refactor: Enhance Assembly Editor with Language Definition and Toolset Integration

- Introduced a new language definition for the 65816 assembly language, improving syntax highlighting and code editing capabilities.
- Updated the AssemblyEditor to utilize the new language definition and integrated a toolset for file management actions, enhancing user experience.
- Refactored the file handling logic to support dynamic file opening and saving, ensuring better resource management within the editor.
- Removed deprecated tab view code, transitioning to a more modular card-based layout for active files, improving UI responsiveness and organization.

src/app/editor/sprite/sprite_editor.h

@@ -8,6 +8,7 @@
 #include "app/editor/editor.h"
 #include "app/editor/sprite/zsprite.h"
 #include "app/gui/canvas.h"
+#include "app/gui/editor_layout.h"
 #include "app/rom.h"
 
 namespace yaze {
@@ -80,6 +81,11 @@ class SpriteEditor : public Editor {
    * @brief Draws the animation frames manager.
    */
   void DrawAnimationFrames();
+  void DrawToolset();
+
+  // Card visibility
+  bool show_vanilla_editor_ = true;
+  bool show_custom_editor_ = false;
 
   ImVector<int> active_sprites_; /**< Active sprites. */