Incorrect PrimalStatus if termination is not optimal

[odow]

Juniper reports the PrimalStatus as INFEASIBLE_POINT when the problem is not optimal: https://github.com/lanl-ansi/Juniper.jl/blob/053661ebc023ff4534210207f9ca40c0ff42fca0/src/MOI_wrapper/results.jl#L29-L39

This is incorrect, because sometimes the point is actually feasible. If we can prove feasibility, it should be FEASIBLE_POINT, otherwise it should be something like UNKNOWN_RESULT_STATUS

First reported on Discourse: https://discourse.julialang.org/t/obtaining-sub-optimal-results-from-the-model-when-the-time-limit-is-reached/85635