[tests] Move general function for MetaMod build to supplementary.py

Outputs_Bayes_None_Calib/emcee_sampler.h5

src/bayesvalidrox/surrogate_models/exp_designs.py

src/bayesvalidrox/surrogate_models/supplementary.py

tests/test_ExpDesign.py

tests/test_MetaModel.py

tests/test_PolynomialChaosEmulator.py

tests/test_SequentialDesign.py

tests/test_engine.py

tests/test_supplementary.py