Add 'Lost and Found' Road Hazard Dataset

[hermannsblum]

This PR adds the Lost and Found dataset.

I mostly followed the code from PR #225 as the datasets follow the same structure, but added a script to generate fake-data.

The gist of the dataset.info files is here.

This is my first contribution, so please excuse if I missed some step, I tried to follow the contributing guidelines closely.

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