epic: refactor SDL2_Renderer usage to IRenderer and queued texture rendering

- Updated the testing guide to clarify the testing framework's organization and execution methods, improving user understanding.
- Refactored CMakeLists to include new platform-specific files, ensuring proper integration of the rendering backend.
- Modified main application files to utilize the new IRenderer interface, enhancing flexibility in rendering operations.
- Implemented deferred texture management in various components, allowing for more efficient graphics handling and improved performance.
- Introduced new methods for texture creation and updates, streamlining the rendering process across the application.
- Enhanced logging and error handling in the rendering pipeline to facilitate better debugging and diagnostics.

src/app/emu/emu.cmake

@@ -5,7 +5,7 @@ if (NOT YAZE_MINIMAL_BUILD AND APPLE)
     MACOSX_BUNDLE
     app/main.cc
     app/rom.cc
-    app/core/platform/app_delegate.mm
+    app/platform/app_delegate.mm
     ${YAZE_APP_EMU_SRC}
     ${YAZE_APP_CORE_SRC}
     ${YAZE_APP_EDITOR_SRC}