Fixing FJ bugs, Termination status and MIP GAP parameters

[rgsl888prabhu]

 Recently Solution.termination_status was changed to an enum so that we can translate between strings and ints for termination status.  When the value is set, it needs to be cast into the correct enum so that we can return the name later in Solution.get_termination_reason().
    
    Authors:
      - Trevor McKay (https://github.com/tmckayus)
    
    Approvers:
      - Rajesh Gandham (https://github.com/rg20)

This PR fixes FJ bugs (feasible solution turned infeasible, objective/violation exploding to infinity, tolerance issues, LHS numerical issues), adds some quality improvements, FJ regression tests, and the ability to save problem_t instances to a MPS file for later debugging.
    
    Authors:
      - Alice Boucher (https://github.com/aliceb-nv)
    
    Approvers:
      - Akif ÇÖRDÜK (https://github.com/akifcorduk)
      - Trevor McKay (https://github.com/tmckayus)

   Hook up MIP Gap parameters and add info about number of nodes explored and simplex iterations, other fixes (#2463)
    
    Hooks up the MIP gap absolute and relative parameters in branch and bound
    
    Returns info about the number of nodes explored and simplex iterations performed.
    
    This PR also:
    * Switches LP from returning solve time in seconds rather than milliseconds
    * Fixes an issue on degme where dual simplex not stopping when PDLP was already finished.
    * Remove mention of LPs in standard form. Since we don't require the LP to be in standard form.

FJ bug fixes, tests and improvements (#2458)
    
    This PR fixes FJ bugs (feasible solution turned infeasible, objective/violation exploding to infinity, tolerance issues, LHS numerical issues), adds some quality improvements, FJ regression tests, and the ability to save problem_t instances to a MPS file for later debugg
ing.
       
    Authors:
      - Alice Boucher (https://github.com/aliceb-nv)
    
    Approvers:
      - Akif ÇÖRDÜK (https://github.com/akifcorduk)
      - Trevor McKay (https://github.com/tmckayus)

[rg20]

LGTM!

[rgsl888prabhu]

/merge