Add metrics of models in abs2gal
requested to merge 415-add-a-tool-that-allow-to-estimate-the-size-of-the-model-related-to-the-asset-type into master
added an option to compute and print metrics for models during abs2abs and abs2gal. Metrics include:
- initial ABS size
- ABS slice size
- goal size (in number of potential states)
- parametric GAL size generated by abs2gal
- flat GAL size generated by GAL flatten