[OMON-406] Add batch size and group id to Pull example (#313)

Author: awegrzyn

examples/13-PullClient.cxx

@@ -12,7 +12,7 @@ int main()
   /// List of topics to subscribe
   std::vector<std::string> topics = {"cru.link_status"};
   /// Connect to server
-  auto client = MonitoringFactory::GetPullClient("adam-kafka:9092", topics);
+  auto client = MonitoringFactory::GetPullClient("adam-kafka:9092", topics, "link-status-consumer");
   for (;;) {
     auto metrics = client->pull();
     if (!metrics.empty()) {

src/Transports/KafkaConsumer.cxx

@@ -54,7 +54,7 @@ KafkaConsumer::KafkaConsumer(const std::string& url, const std::vector<std::stri
 std::vector<std::pair<std::string, std::string>> KafkaConsumer::pull()
 {
   std::vector<std::pair<std::string, std::string>> received;
-  size_t batch_size = 5;
+  size_t batch_size = 10;
   int remaining_timeout = 1000;
   auto start = std::chrono::high_resolution_clock::now();