FTextureRenderTargetResource::GetDisplayGamma

Also [GetSizeZ()](API\Runtime\RenderCore\FTexture\GetSizeZ) GetSizeXY from "FRenderTarget" virtual FIntPoint [GetSizeXY() const ](API\Runtime\Engine\FRenderTarget\GetSizeXY)override = 0; Render target resource should be sampled in linear color space