CMake: add lib skeleton and google-tests

google-tests/test1.cpp

@@ -0,0 +1,15 @@
+//
+// Created by david on 28.02.2026.
+//
+#include <gtest/gtest.h>
+#include "library.h"
+
+// Demonstrate some basic assertions.
+TEST(HelloTest, BasicAssertions) {
+    // Expect two strings not to be equal.
+    EXPECT_STRNE("hello", "world from test1.cpp");
+    // Expect equality.
+    EXPECT_EQ(7 * 6, 42);
+    printf("asdf");
+    hello();
+}