UnitTests: Add build script and move current tests to "tests/Engine" directory (from "tests/Nazara")

Former-commit-id: 5639305bbdbb69ad6f6f282df6c6de930220b57f

tests/Engine/Core/Clock.cpp

@@ -0,0 +1,30 @@
+#include <Nazara/Core/Clock.hpp>
+#include <Nazara/Core/Thread.hpp>
+#include <Catch/catch.hpp>
+
+SCENARIO("Clock", "[CORE][CLOCK]")
+{
+	GIVEN("A clock paused")
+	{
+		nzUInt64 initialTime = 1;
+		NzClock clock(initialTime, true);
+
+		WHEN("We get time")
+		{
+			THEN("Time must be the initialTime")
+			{
+				REQUIRE(clock.GetMicroseconds() == initialTime);
+			}
+
+			AND_WHEN("We unpause it")
+			{
+				clock.Unpause();
+				THEN("Time must not be the initialTime")
+				{
+					NzThread::Sleep(1);
+					REQUIRE(clock.GetMicroseconds() != initialTime);
+				}
+			}
+		}
+	}
+}