Add rdkafka client

Adds rdkafka dependency, rdkafka client,
and notification for file close event

receiver/src/request_handler/request_handler_kafka_notify.cpp

+#include "request_handler_kafka_notify.h"
+#include "../request.h"
+
+namespace asapo {
+
+Error RequestHandlerKafkaNotify::ProcessRequest(Request* request) const {
+    if (!kafka_client_) {
+        //client was not initialized, ignore
+        return nullptr;
+    }
+
+    std::string message = "{"
+            "\"event\":\"IN_CLOSE_WRITE\","
+            "\"path\":\"" + request->GetFileName() + "\""
+    "}";
+
+    return kafka_client_->Send(message, "asapo");
+}
+
+StatisticEntity RequestHandlerKafkaNotify::GetStatisticEntity() const {
+    return StatisticEntity::kNetwork;
+}
+
+RequestHandlerKafkaNotify::RequestHandlerKafkaNotify() : kafka_client_{GetKafkaClient()} {
+}
+}
\ No newline at end of file

receiver/src/request_handler/request_handler_kafka_notify.h

+#ifndef ASAPO_REQUEST_HANDLER_KAFKA_NOTIFY_H
+#define ASAPO_REQUEST_HANDLER_KAFKA_NOTIFY_H
+
+#include "request_handler.h"
+#include "asapo/kafka_client/kafka_client.h"
+
+namespace asapo {
+
+class RequestHandlerKafkaNotify final : public ReceiverRequestHandler {
+  public:
+    RequestHandlerKafkaNotify();
+    StatisticEntity GetStatisticEntity() const override;
+    Error ProcessRequest(Request* request) const override;
+  private:
+    std::unique_ptr<KafkaClient> kafka_client_;
+};
+
+}
+
+#endif //ASAPO_REQUEST_HANDLER_KAFKA_NOTIFY_H