Sagemath Component of CoWasm

The goal of the packages in this directory is a full port of https://www.sagemath.org/ to WebAssembly.

This is a work in progress, which starts with copying over some packages from here.

WARNING: Unlike the rest of CoWasm, there is code in this directory that is licensed under the GPL. No code in the other packages (core, python, web, etc.,) depends on this code.