Create a new Cbc Optimizer.

Variable names

By default, Cbc.jl will not pass variable names to the C model because, in some instances, this has caused segfaults. Enable names being passed to the C model using:

using JuMP, Cbc
model = Model(
    optimizer_with_attributes(Cbc.Optimizer, Cbc.SetVariableNames() => true),

Create an IndexMap mapping the variables and constraints in OptimizerCache to their corresponding 1-based columns and rows.