Country/region are specific to wireless because of regulatory requirements.
The closest you'll get for generic networks is using...
https://developer.cisco.com/meraki/api-v1/get-organization-networks/
...and the timeZone parameter.
Even with wireless, the only way Dashboard 'knows' what the country it is will be through configuration you input in the first place (auto-detection of wireless country region is absolutely not reliable!)
So if you want to know the country, add it as a tag when configuring the network, then you can always read the tag later - this is what we do.