How to set the file target for a high res screenshot

[Flash7]

And this is how you basically do it:

		UGameViewportClient* ViewportClient = TheWorld->GetGameViewport();
		ViewportClient->OnScreenshotCaptured().Clear();
		ViewportClient->OnScreenshotCaptured().AddLambda(
			[ScreenshotFilePath](int32 SizeX, int32 SizeY, const TArray<FColor>& Bitmap)
		{
			// Make sure that all alpha values are opaque.
			TArray<FColor>& RefBitmap = const_cast<TArray<FColor>&>(Bitmap);
			for(auto& Color : RefBitmap)
				Color.A = 255;

			TArray<uint8> CompressedBitmap;
			FImageUtils::CompressImageArray(SizeX, SizeY, RefBitmap, CompressedBitmap);
			FString ScreenshotFilePath = GetScreenshotFilePath(CleanSlotFileName);
			FFileHelper::SaveArrayToFile(CompressedBitmap, *ScreenshotFilePath);
		});