quantresearch1

ENH: add sparse nonzero functionality to min, max, argmin, argmax

27

DISCLAIMER: This is simply the PR from [dloney:sparse_nonzero](https://github.com/dloney/scipy/tree/sparse_nonzero), gh-11899, merged with main. I have asked on his PR if I could pick it up given it's been stale for two...

add qp support for highs

9

## Fixes #3381 . ## Summary/Motivation: HiGHS can solve quadratic programming (QP) models, which contain an objective term x.T @ Q @ x where the Hessian matrix Q is positive...