[PEP] Solver Interfaces still to be ported

[mrmundt]

Summary

This is the big list of interfaces that need to be ported over to the redesign effort.

• BARON - @mrmundt (and others?)
• GAMS - @AnhTran01
• SCIP - @michaelbynum
• KNITRO - @eminyouskn
• Xpress - Ben?
  • LP
  • MPS
  • direct/persistent
• maingo - ?
• CPLEX - ?
  • MNLP
  • LP
  • NL
  • MPS
  • direct/persistent
• Gurobi - @michaelbynum , maybe eventually @eminyouskn
  • MNLP - @emma58
  • LP
  • NL
  • MPS
  • direct/persistent drafts (needs finalization) - @michaelbynum
• Generic ASL - @jsiirola
• conopt - ?
• scipy - ?
• MOSEK - @eminyouskn
• cyipopt - @mrmundt
• cuopt - @michaelbynum
• cbc - ?
• glpk - ?
• SAS - Phillip? Maybe?
• mpec - ? (delete this maybe?)

Metasolvers like MindtPy, etc., should probably come after.