Fix init-countries script

[sameh-farouk]

What's Changed:

• Recently, we observed that the restcountries.com API was unreliable, so we have decided to self-host the JSON data.
• The script will now check if the geo data already exists in the database, so the initialization step can be skipped without any issues.
• If the data does not exist in the DB and an error occurs while fetching or inserting this data, the processor should not start syncing. Instead, we will exit with an error to avoid starting with missing data.
• Handle partial geo data in DB (on conflict) by updating the entries instead of panicking.

Related Issue:
#181 (comment)