Develop a Python program to upload population values per country to the database

Exposure-finalizer uses population values stored in the Metadata table. These are stored in a CSV file in the gde-docs repository. This small program should simply upload the population values from the CSV file into the Metadata table. It should also have an option to overwrite existing population values in the Metadata table for easier handling.

\rfc @laurens @gislars @kasra