Updated project version to 5.4.0.

Updated the version numbers used in reference manual from 5.2.0 to 5.4.0 as expected.

TODO: Make the version parametric in the md doc.

Author: ihsandemir

CMakeLists.txt

@@ -17,7 +17,7 @@
 cmake_minimum_required(VERSION 3.10)
 
 project(hazelcast-cpp-client
-        VERSION 5.3
+        VERSION 5.4
         DESCRIPTION "Hazelcast C++ Client"
         LANGUAGES CXX)