feat: Implement lazy initialization for Emulator and Renderer

- Updated Emulator to support optional lazy initialization of the renderer, enhancing flexibility during runtime.
- Introduced a new method in IRenderer for creating textures with specific pixel formats, improving texture management for the emulator.
- Refactored texture command processing in Arena to handle empty queues more gracefully.
- Enhanced SDL2Renderer to support the new texture creation method, ensuring compatibility with emulator requirements.

src/app/gfx/arena.cc

@@ -33,7 +33,7 @@ void Arena::QueueTextureCommand(TextureCommandType type, Bitmap* bitmap) {
 }
 
 void Arena::ProcessTextureQueue(IRenderer* renderer) {
-  if (!renderer_) return;
+  if (!renderer_ || texture_command_queue_.empty()) return;
 
   for (const auto& command : texture_command_queue_) {
     switch (command.type) {