Causal queries with approxLP using crema 0.2.x

[rcabanasdepaz]

In branch dev-crema020-iss24 approxLP is not working for calculating causal queries due to an unfeasible exception. This is based on crema 0.2.2. Check the following examples where it fails.

https://github.com/IDSIA/credici/blob/dev-crema020-iss24/examples/not_working/EquationlessFromFile.java

https://github.com/IDSIA/credici/blob/dev-crema020-iss24/examples/not_working/PartyCounterfactuals.java

https://github.com/IDSIA/credici/blob/dev-crema020-iss24/examples/not_working/Queries.java