Improve Meson build

[tobiasdiez]

• Run meson-ci for MacOS #38879
• Use the meson-based pyproject.toml for distribution on pypi
• Replace old setuptools-based build system in sage-the-distro by meson-based build
• Migrate refined dependency checks to meson (e.g. presence of certain header files or macros, version constraints). At the moment, meson simply checks for the presence of the library in most cases.
• Refine dependency declarations. Currently, cython files in a same directory are declared to have the same dependencies. Thus if one of the dependencies is missing, then the whole folder is not built. In reality, only some of the cython files depend on a given dependency, and ideally we would like to skip only these files that really need the dependency.
• Migrate sage.features to use mostly built-time discovery using meson (see Migrate bliss extension to meson #38836 (comment) and following comments for discussion).
• Maybe migrate optional distributions to meson (along the lines of Migrate bliss extension to meson #38836)
• Maybe migrate test suits to use meson (perhaps along the lines of Update portability tests to use Meson #37077).

Upstream issues:

• Add pkgconfig files