[FEA] Add example of multihot data with hugectr

[benfred]

We should update our movielens example for HugeCTR to incorporate the multihot 'genres' field since HugeCTR supports multihot parquet inputs now.

We should be able to use the same preprocessing script for HugeCTR with movielens that we do with TensorFlow now - but we will need to move the existing hugectr movielens examples to be in the same folder for both training and inference.

[rnyak]

@benfred there is a PR for that: https://github.com/NVIDIA/NVTabular/pull/1021

shall we consider it?

[albert17]

@rnyak @benfred what is the plan for this and #1021 ?