added support for Collection Functions

new supported operations: min,max,sum,avg
new supported time scopes: interval,startup

added unit test to verify that each collection function returns correct
timestamp and value

Tested:
- POST/GET on telemetry features in bmcweb, no regression detected
- Using dbus API metric with collection function works as expected

Change-Id: Ib364c433915e07fd7a102f00109525362c40ab8a
Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
diff --git a/src/types/collection_duration.hpp b/src/types/collection_duration.hpp
index ddeb9cc..2db8278 100644
--- a/src/types/collection_duration.hpp
+++ b/src/types/collection_duration.hpp
@@ -6,6 +6,7 @@
 #include <nlohmann/json.hpp>
 
 #include <chrono>
+#include <cstdint>
 
 BOOST_STRONG_TYPEDEF(Milliseconds, CollectionDuration)