[FEA] Post context fusion using T4rec api

[vivpra89]

🚀 Feature request

https://github.com/NVIDIA-Merlin/competitions/blob/3734d8aef94c73f5f8a572789aca1a17f69b12a5/SIGIR_eCommerce_Challenge_2021/task1_session_based_rec/2-models/sigir_ecom_transformers/recsys_meta_model.py#L605

Motivation

SIGIR_eCommerce_Challenge_2021 solution from nvidia used a post-context fusion of search embeddings. Is there a way to introduce post context fusion using t4rec api and package.

[karunaahuja]

+1, could be very helpful!