rework client using async api

autotest/client_autotest/CMakeLists.txt

@@ -0,0 +1,24 @@
+set(SRCS
+    client_autotest.cc
+    main.cc
+    )
+
+# Common libraries to link.
+set(LIBS
+    webcc
+    jsoncpp
+    GTest::GTest
+    )
+
+if(UNIX)
+    # Add `-ldl` for Linux to avoid "undefined reference to `dlopen'".
+    set(LIBS ${LIBS} ${CMAKE_DL_LIBS})
+endif()
+
+set(TARGET_NAME client_autotest)
+
+add_executable(${TARGET_NAME} ${SRCS})
+
+target_link_libraries(${TARGET_NAME} ${LIBS})
+
+set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests")