Set model does not update object data in v0.6

[jalving]

The set_model functionality does not update node object data in v0.6. The following snippet fails.

using Plasmo
using JuMP
using HiGHS

graph = OptiGraph()
@optinode(graph, n1)
@optinode(graph, n2)

m1 = Model()
@variable(m1, x[1:2]>=0)
@objective(m1, Min, sum(x))
set_model(n1, m1)
n1[:x]

This should be a straight-forward fix. We just need to make sure we're copying over JuMP model data.

[jalving]

should be fixed by #119