GPU: Set line width at higher internal resolutions

src/core/settings.h

@@ -12,6 +12,7 @@ struct Settings
 
   GPUBackend gpu_backend = GPUBackend::OpenGL;
   u32 gpu_resolution_scale = 1;
+  u32 max_gpu_resolution_scale = 1;
   
   // TODO: Controllers, memory cards, etc.
 };