Fetch a site file for a country from the malariaverse sitefile server.
fetch_site.Rd
The site file is identified by its country code, and optionally the admin_level, urban/rural setting and version of the site files. The latest packet from the server matching these parameters is used. By default, calling `fetch_site()` with only `iso3c` downloads the latest available version. For reproducibility and stable workflows, it is strongly recommended to specify `version`, `admin_level`, and `urban_rural` explicitly, or to download and store site files locally. Otherwise, downstream pipelines may break when new site file versions are released.