Support for re-building the WOMD dataset

[daphnecor]

Description

This PR supports the re-building of the JSON files from the Waymo Open Motion Dataset.

Note: This PR is co-authored by @nadarenator

Todo's

• [x] Download files from WOMD and add docs on how to achieve this
• [x] Update Python and package versions (must use Python 3.10 as 3.11 does not work with waymo-open-dataset-tf-2-12-0==1.6.4)
• [x] Test file conversion from scenario format -> json
• [x] Use the scenario id as the JSON file names so that files can easily be aligned with Waymax
• [x] Test if new files work with the simulator
• [x] Use GitHub LFS to host a couple of small datasets so that users can readily download them + update that part of the docs
• [x] Add docs

Todo's

• [ ] Adding a subset of the dataset to github lfs
• [x] Mention it in the readme
• [x] Rebase over main

[nadarenator]

Things to address:

• Some scenes are iterated through but don't get saved, could be due to raw record-level anomalies and how tensorflow handles them.
• Will have to downgrade to older version of waymo-open-dataset due to incompatibility with python 3.11. Unless significant changes in protobuf this should be okay, else we will have use a separate python env just for re-building.

[daphnecor]

• Will have to downgrade to older version of waymo-open-dataset due to incompatibility with python 3.11. Unless significant changes in protobuf this should be okay, else we will have use a separate python env just for re-building.

Either we can do that, or we change to Python 3.10 (which is what I've been doing so far, see changes in the readme)