Callback for Text2Image Pipeline, Flux pipeline fix

[likholat]

Callback sample with decoding:

auto callback = [&](size_t step, ov::Tensor& intermediate_res) -> bool {
      std::cout << "Image generation step: " << step << std::endl;
      if (step == 9) {
          ov::Tensor img = pipe.decode(intermediate_res);
          imwrite("callback_image_%d.bmp", img, true);
          return true;
      }
      return false;
  };

[eaidova]

is there any plans also demonstrate decode method usage somewhere in readme?

[likholat]

#1237

[ilya-lavrenov]

looks like it should also perform unpack_latents ?

[likholat]

#1237