Add MILP solver backends for HiGHS via highspy

[mkoeppe]

HiGHS is developing its own Python interface in https://github.com/ERGO-Code/HiGHS/tree/master/src/interfaces/highspy (using pybind11); tableau data access methods yet to be done

• OSI interface needs updating ERGO-Code/HiGHS#525 (comment)

Component: linear programming

Issue created by migration from https://trac.sagemath.org/ticket/33919

[Ishaanjolly]

comment:1

Can I work on this ticket?

[mkoeppe]

comment:2

Sure. Start with creating packages highs and highspy - https://doc.sagemath.org/html/en/developer/packaging.html