Temporarily Adjust NL Writer Feasibility Tolerance within PyROS

[shermanjasonaf]

Summary/Motivation:

Allow PyROS to temporarily adjust the NL writer feasibility tolerance before/after solving subproblems.

This change has been instituted to circumvent encounters with InfeasibleConstraintException arising from discrepancies between the Pyomo NL writer feasibility tolerance (pyomo.repn.plugins.nl_writer.tol) and the default feasibility tolerances for NL writer-based subsolvers, such as IPOPT, for which the default value of the (unscaled) feasibility tolerance is looser.

Changes proposed in this PR:

• Allow PyROS to temporarily adjust the Pyomo NL writer feasibility tolerance.
• Fix errors in PyROS restoration of IPOPT time limit specification for IPOPT >= 3.14.0.

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