Implementing IntTower for retrieval

[vs385]

🌟 New model addition

Model description

This model is a slight improvement over the TwoTower architecture as it allows the two towers to interact not just on the last layer and seems to be producing better results at identifying more closely user-item preferences/interactions than TT does.
IntTower: the Next Generation of Two-Tower Model for Pre-Ranking System
https://arxiv.org/pdf/2210.09890.pdf

Open source status

• the model implementation is available: https://github.com/archersama/IntTower
• who are the authors: @archersama

[rnyak]

@vs385 thanks for your request. we are welcoming PRs from community if you would like to work on this enhancement and create a PR.