New Hestia emissions models

Hestia has an [extensive set of environmental models](https://gitlab.com/hestia-earth/hestia-engine-models/), but [not enough](https://www.bikeshepherd.org/what-does-n1-mean-in-cycling/). This topic will adapt another existing published farm-stage model for Hestia.

If possible, it would be interesting if this model could be implemented in a more generic fashion, and not suitable only for Hestia infrastructure.

Tasks:

- [ ] Select model from candidate list
- [ ] Implement model basics in Python
- [ ] Add tests and documentation
- [ ] Publish and integrate into Hestia database workflow

Suggested lead: Guillaume Royer

Start by reviewing the linked Hestia environmental models and selecting a candidate model for adaptation. Implement the model basics in Python, then add tests and documentation. Done means the model is published and integrated into the Hestia database workflow, with generic reuse considered where possible.

Written by the indexing model from the issue text.