feat core: do not use tuple header in LRU cache components

Tests: протестировано CI
8d688c7f2bd7feb609f0dec9990d2dff683433c7

core/include/userver/utils/impl/cached_time.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <chrono>
-#include <tuple>
 
 USERVER_NAMESPACE_BEGIN
 
@@ -15,9 +14,14 @@ using SteadyTimePoint = std::chrono::steady_clock::time_point;
 // be costly, so as an optimization we cache now() globally.
 void UpdateGlobalTime();
 
+struct SystemAndSteadyTimePoints {
+  SystemTimePoint system;
+  SteadyTimePoint steady;
+};
+
 // Note: the two time points are not synchronized. They may also come from
 // different 'UpdateGlobalTime' calls.
-std::tuple<SystemTimePoint, SteadyTimePoint> GetGlobalTime();
+SystemAndSteadyTimePoints GetGlobalTime();
 
 }  // namespace utils::impl
 

core/src/utils/impl/cached_time.cpp

@@ -23,7 +23,7 @@ void UpdateGlobalTime() {
                          std::memory_order_relaxed);
 }
 
-std::tuple<SystemTimePoint, SteadyTimePoint> GetGlobalTime() {
+SystemAndSteadyTimePoints GetGlobalTime() {
   return {system_clock_now.load(std::memory_order_relaxed),
           steady_clock_now.load(std::memory_order_relaxed)};
 }