Use a set of CMakeLists.txt and package.xml files for server and test

[Barry-Xu-2018]

I encountered an issue when releasing the persist_parameter_server package.

With the current directory structure, running "catkin_generate_changelog --all" does not work correctly. It creates a CHANGELOG.rst file in the test directory.

I merged the CMakeLists.txt files from server and test directories into a single file and placed it in the top-level directory of the repository. To compile the code in the test directory, the cmake variable "CLIENT_TEST_DEMO=ON" need to be set.
Move the package.xml file from the server directory to the top-level directory of the repository.

At the same time, I change the package name to "persist_parameter_server" to keep it the same as ros/rosdistro#47829.

[Barry-Xu-2018]

I found that making changes will affect the tests. I also need to modify other files.

[Barry-Xu-2018]

Regarding the CI test errors, according to the log, the old script is still being used for execution.

[fujitatomoya]

Regarding the CI test errors, according to the log, the old script is still being used for execution.

i believe that we need to update test_launch.py to use new package name which is persist_parameter_server? that is why parameter server is not online during test, see https://github.com/fujitatomoya/ros2_persist_parameter_server/actions/runs/18122360082/job/51569615867?pr=61