Subsystem monitored line issue

[yonghongchen8]

In this code, https://github.com/NREL-Sienna/irtoc_experiments/blob/main/SplitArea_ReserveDeliverability/rts_demo_yc.jl,
we assigned "B28" to subsystem "b" and "A28" to subsystem "a".

l = get_component(ACBranch, sys2, "B28")
PowerSystems.add_component_to_subsystem!(sys2, "b", l)

l = get_component(ACBranch, sys2, "A28")
PowerSystems.add_component_to_subsystem!(sys2, "a", l)

We expect only "A28" flow limit is enforced in "a", and only "B28" flow limit is enforced in "b".
However, as shown at the end of the code, all monitored lines are enforced in both subsystems.

#ulia> axes(uc2b.constraints[InfrastructureSystems.Optimization.ConstraintKey{RateLimitConstraint, MonitoredLine}("ub")])
#(["B28", "CA-1", "CB-1", "A28", "AB1"], 1:24)

#julia> axes(uc2a.constraints[InfrastructureSystems.Optimization.ConstraintKey{RateLimitConstraint, MonitoredLine}("ub")])
#(["B28", "CA-1", "CB-1", "A28", "AB1"], 1:24)

[m-bossart]

Possibly related to: Sienna-Platform/PowerSimulations.jl#1409