Refactor CMakeLists

Closes #2471
Closes #1816

example/advanced/server-flex/CMakeLists.txt

@@ -1,5 +1,6 @@
 #
 # Copyright (c) 2016-2017 Vinnie Falco (vinnie dot falco at gmail dot com)
+# Copyright (c) 2024 Mohammad Nejati
 #
 # Distributed under the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -7,25 +8,15 @@
 # Official repository: https://github.com/boostorg/beast
 #
 
-if (OPENSSL_FOUND)
-    GroupSources(include/boost/beast beast)
-    GroupSources(example/common common)
-    GroupSources(example/advanced/server-flex "/")
+add_executable(advanced-server-flex
+    Jamfile
+    advanced_server_flex.cpp)
 
-    add_executable (advanced-server-flex
-        ${BOOST_BEAST_FILES}
-        ${PROJECT_SOURCE_DIR}/example/common/server_certificate.hpp
-        Jamfile
-        advanced_server_flex.cpp
-    )
+target_include_directories(advanced-server-flex
+    PRIVATE ${PROJECT_SOURCE_DIR})
 
-    set_property(TARGET advanced-server-flex PROPERTY FOLDER "example-advanced-server")
-    
-    target_link_libraries (advanced-server-flex
-        OpenSSL::SSL OpenSSL::Crypto
-        lib-asio
-        lib-asio-ssl
-        lib-beast
-        )
+target_link_libraries(advanced-server-flex
+    PRIVATE Boost::beast OpenSSL::SSL OpenSSL::Crypto)
 
-endif()
+set_target_properties(advanced-server-flex
+    PROPERTIES FOLDER "example-advanced-server")