[API guide] Funtap and Playio market examples added to IAP v4 receipt verification¶

We are adding Funtap and Playio market request/response examples to the IAP v4 receipt verification API guide.

Key updates¶

1. IAP v4 receipt verification (Hive Server API v4)
   • Funtap and Playio market tabs added to request examples
   • Funtap and Playio market tabs added to response examples