[util] Introduce a SetMockTime that takes chrono time

src/util/time.cpp

@@ -53,6 +53,11 @@ void SetMockTime(int64_t nMockTimeIn)
     nMockTime.store(nMockTimeIn, std::memory_order_relaxed);
 }
 
+void SetMockTime(std::chrono::seconds mock_time_in)
+{
+    nMockTime.store(mock_time_in.count(), std::memory_order_relaxed);
+}
+
 std::chrono::seconds GetMockTime()
 {
     return std::chrono::seconds(nMockTime.load(std::memory_order_relaxed));