code: def rpc_get_subdomains_owned_by_address(self, address, **con_info):
          
          if not check_address(address):
              return {'error': 'Invalid address', 'http_status': 400}
  
          res = get_subdomains_owned_by_address(address)
          return self.success_response({'subdomains': res})
docs: Get the list of subdomains owned by an address.
          Return {'status': True, 'subdomains': ...} on success
          Return {'error': ...} on error