While writing CMake-Template, and working on the octopus project, I have encountered a few improvements that should be included in the cmake project. First I want to finish and document CMake-Template about these practices, then I will port them here. Some of the changes are:

• Make fortran, test etc. as their own sub-project. That would allow to build/install these projects on top of a built-in spglib library, e.g. the python bindings
• Add CMAKE_MESSAGE_CONTEXT for better message navigation downstream
• Add FeatureSummary for a nice output of the options enabled
• Better packaging tests using native ctest --build-and-test
• More re-usable CI workflows. In principle we could import the workflows in CMake-Template directly pinning it to main, in which the CI maintenance can be offloaded. I can migrate pre-commit, doc-test and build-wheel, more-or-less as they are now, but test would need more work to de-tangle it from the python test matrix