trajdata: A unified interface to many trajectory forecasting datasets

Lots of new features and internal changes in this version! Namely, we've implemented: Initial (beta) support for nuPlan! So far, we've only really tested the nuPlan mini split and are waiting for the devkit to be released more widely (e.g., on PyPI) before supporting the rest of the dataset. A new VectorMap object which provides users a unified interface to dataset maps (if available). It supports efficient geometric querying for nearest lanes, accessing raw polylines and polygons, traffic light status (beta, and only currently implemented for nuPlan), as well as basic utilities like interpolation and projection. We also provide new example scripts (examples/{map_api, simple_map_api, lane_query}_example.py) demonstrating some functions of the new vector map API. NOTE: The way lane querying is done will change slightly in the future, currently heading is taken as an input but this will be removed explicitly in the future. NOTE: While many of the typical map elements from AV datasets are included (i.e., road lanes, driveable areas, pedestrian crosswalks and walkways), not all are. Keep an eye out for future updates which address this and expand upon our map format! A MapAPI object that manages and creates/loads VectorMap objects. Changes to some of the UnifiedDataset init arguments to distinguish between vector map parameters and rasterized map parameters. The (beta) capability to store and load already-computed batch elements for significantly faster loading later. See examples/cache_and_filter_example.py for an example of its usage. NOTE: While we provide an initial implementation of this functionality, it is not very efficient right now and uses a lot of space on disk. Look out for future updates that improve upon this! Internal code refactors to put utilities and other classes in more sensible locations (e.g., now all utilities live within utils/, they were more spread out before). Added utilities (and associated tests) for converting between batch types. Added tests for a few map functions (to be expanded). If upgrading from a previous version, please make sure to delete your unified data cache and recreate it using this latest version of trajdata.If you use this software, please cite it as follows