redesign cmake entrypoint

[kiwifb]

This is a sort of follow up to #413 and #414. In sage-on-gentoo we discovered that the presence of scikit-build-core breaks the building sagemath (cschwan/sage-on-gentoo#783). scikit-build-core also happens to be an indirect dependency for building sagemath's documentation.
On the basis that the presence of setuptolls_rust does not break sagemath's build, I studied the difference with scikit-build-core. I noticed that the elements `bundled in the single "finalize_distribution_options" entrypoint in scikit is split between two different setuptools entrypoints.
This PR reproduce that setup and does a bit of clean up. The bundling of the old _prepare_extension_detection and _prepare_build_cmake_command into finalize_distribution_options being redundant after attributing them directly to separate entrypoints. I also renamed the functions to better characterise them.

Using this PR, sagemath builds without problems and pyzmq, which uses scikit-build-core also builds properly.

[henryiii]

I think it might be better to match the entry points and names?

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 81.96%. Comparing base (d9c41f9) to head (cbbe4c0).
Report is 91 commits behind head on main.

Files with missing lines	Patch %	Lines
src/scikit_build_core/setuptools/build_cmake.py	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #768      +/-   ##
==========================================
- Coverage   81.98%   81.96%   -0.02%     
==========================================
  Files          68       68              
  Lines        3919     3921       +2     
==========================================
+ Hits         3213     3214       +1     
- Misses        706      707       +1     

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[henryiii]

Could you try it with my changes and see if that fixes sagemath?

[henryiii]

(pyzmq doesn't use the setuptools plugin, so it should be fine. I think we only have ~1 user so far of the setuptools plugin.)

[kiwifb]

I just checked and sagemath still builds with your newest changes. I must say, I was not sure it would.

[henryiii]

This makes sure nothing is injected unless a cmake_* keyword is present. Sagemath doesn't have one of those, so it's fine. :)

The injection should have been pretty safe, but this is safer.

[henryiii]

Thanks!