1.0.8 - A few extra features as well as a hotfix related to rasterized maps

The extra features are:

• Enabling the limiting of the maximum number of neighbors included in an agent-centric batch element.
• Enabling the returning of only ego-centric batches.

The hotfix refers to bringing back the original format of datasets' map rasterizations (prior to v1.0.7 you could choose between having RGB channels or semantic channels, e.g., nuScenes has 7, however v1.0.7 inadvertently removed the latter and so this hotfix brings it back). Users can request rasterized maps in a dataset's original format by adding "original_format": True to the map_params dict. By default, it is False.

NOTE: Changing the desired format of rasterized maps necessitates re-caching maps in the unified data cache.