query cities of a specific state using iso of country

[MartinsOnuoha]

currently the query for cities requires country and state payload. We need to have iso2 and state or iso3 and state`. or both.

Current payload:

{
  "country": "Nigeria",
  "state": "Lagos"
}

Required payload:

{
  "iso2": "NG",
  "state" "Lagos"
}

or

{
  "iso3": "NGN",
  "state": "Lagos"
}