Add timestamp function

Reviewers: teon.banek, buda

Reviewed By: teon.banek

Subscribers: mferencevic, pullbot

Differential Revision: https://phabricator.memgraph.io/D1452

tests/benchmark/query/planner.cpp

@@ -3,6 +3,7 @@
 #include <benchmark/benchmark_api.h>
 
 #include "database/graph_db.hpp"
+#include "database/graph_db_accessor.hpp"
 #include "query/frontend/semantic/symbol_generator.hpp"
 #include "query/plan/cost_estimator.hpp"
 #include "query/plan/planner.hpp"