CHEVROLET BOLT EUV 2022: Add a simple neural feed forward

[nuwandavek]

Note: Moving PR from #31255 for simplicity

• We already customize lateral feed-forward for platforms in various ways (Static torque control, torqued, non-linear response etc.).
• This PR introduces a neural feed forward for the CHEVROLET BOLT EUV 2022 platform.
• This is a small 4-layer MLP (262 parameters) that takes in the lateral_acceleration, roll_compensation, vego and aego
• The model was then evaluated in the MLControlsSimulator, allowing easy comparison between the various feed-forward strategies for the Bolt:

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• Examples live in the car:

[simontheflutist]

Did this commit break master-ci? The loader is there, but selfdrive/car/torque_data/neural_ff_weights.json is missing as of this morning's 8d799ec.