Population projections by department

[sebhoerl]

Since January, there is a new data set giving additional details on INSEE's population projections. So far, we only use a data set that takes into account the country-wide projection by age and sex. This data set gives those projections by department:
https://www.insee.fr/fr/statistiques/7747107?sommaire=6652140

• Write the code to read the new data set
• Integrate the new marginals into the projection IPU
• Document the process

Ideally, the users only need to place the ZIP file into the data folder, and then they can select the projection year and the projection scenario (central / high growth / ...) via configuration.