Consider move to cmaketools

[Stagno]

https://pypi.org/project/cmaketools/

Our cmake in setup.py solution is tailor-made and difficult to maintain. It seems from the comments that it has been based on several different snippets from repos and/or blog posts.
Today I wanted to add the cmake dependency on llvm, but i can't think of a way to do this with this setup.

We should switch to an off-the-shelf setup, such as cmaketools. We don't know if this was already considered in the past.