Transition to build system for sage (the library) #14807
Description
Sage ("the library") needs a build system that works inside and outside of sage ("the distribution").
This ticket integrates the build systems for the parts of sagelib into the current toplevel build system.
Depends on #14726
Depends on #14834
Depends on #15102
Depends on #15112
Depends on #15117
Depends on #15123
Depends on #15126
Depends on #15176
Component: distribution
Keywords: sagelib
Branch/Commit: u/felixs/sagelib @ fc097b0
Reviewer: Marc Mezzarobba
Issue created by migration from https://trac.sagemath.org/ticket/14807