Refactor Renderer access and enhance graphics loading functionality

- Replaced instances of Renderer::GetInstance() with Renderer::Get() for consistency across the codebase.
- Updated various rendering methods to streamline bitmap updates and enhance performance.
- Removed unused includes and comments to improve code clarity and maintainability.

src/app/editor/code/memory_editor.h

@@ -4,6 +4,7 @@
 #include "app/core/platform/file_dialog.h"
 #include "app/gui/input.h"
 #include "app/rom.h"
+#include "app/snes.h"
 #include "imgui/imgui.h"
 #include "imgui_memory_editor.h"
 #include "util/macro.h"