Migrate to cmake and refine the code structure (#92)

* migrate to cmake

* move the 3rd party libs

* organize 3rdparty

* update the 3rd party version

* refine the CMakeLists.txt

* update install command

* update install command

* update install command

* update install command

* update dependency

* update the dependency

* update the dependency

* remove CPM.cmake

* remove QtCreator project file

* update cmake file

* improve cmake file

* add cmakew

* use wget

* remove echo

* update the doc

* remove the screenshot

* update the doc

* update the install steps

* check the openconnect version

* update the doc

* update install scripts

* fix install scripts

* improve message

* improve message

* improve install scripts

* improve the version check

* improve the version check

* improve install script

* add version

* organize includes

* add version bump

* update CI

* update CI

* add the release flag

* update message

cmake/Add3rdParty.cmake

@@ -0,0 +1,27 @@
+include(ExternalProject)
+
+function(add_3rdparty NAME)
+    set(oneValueArgs GIT_REPOSITORY GIT_TAG)
+    cmake_parse_arguments(add_3rdparty_args "" "${oneValueArgs}" "" ${ARGN})
+
+    if(EXISTS "${CMAKE_SOURCE_DIR}/3rdparty/${NAME}/CMakeLists.txt")
+        message(STATUS "Found third party locally for ${NAME}")
+
+        ExternalProject_Add(
+            ${NAME}-${PROJECT_NAME}
+            PREFIX ${CMAKE_CURRENT_BINARY_DIR}/${NAME}
+            SOURCE_DIR "${CMAKE_SOURCE_DIR}/3rdparty/${NAME}"
+            INSTALL_COMMAND ""
+            "${add_3rdparty_args_UNPARSED_ARGUMENTS}"
+        )
+        return()
+    endif()
+
+    message(STATUS "Using ExternalProject to download ${NAME}") 
+    ExternalProject_Add(
+        ${NAME}-${PROJECT_NAME}
+        PREFIX ${CMAKE_CURRENT_BINARY_DIR}/${NAME}
+        INSTALL_COMMAND ""
+        "${ARGN}"
+    )
+endfunction()