Make regional multipliers for bulkvolume, porosity and permeability

[olelod]

This PR introduces the possibility of adding regional multipliers for bulkvolume, permeability and porosity.

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Contributor checklist

• 🎉 This PR closes Regional (or trend) tuning parameters #394.
• 📜 I have broken down my PR into the following tasks:
  • Add bulkvolume_mult_regional_scheme, porosity_regional_scheme and permeability_regional_scheme to the model_parameters in _config_parser.py. Default values are individual, meaning no regional multiplier (alternatives are regions_from_sim or global)
  • Add bulkvolume_mult_regional, porosity_regional and permeability_regional to the model_parameters in _config_parser.py. If the *_regional_scheme is individual the priors can be empty, otherwise they need to be defined (same way as the priors for individual tubes - not implemented possibility for different priors in different regions (such as for equilibrium regions or relative permeability)
  • Add bulkvolume_mult_parameter_from_sim_model, porosity_parameter_from_sim_model and permeability_parameter_from_sim_model, telling which region parameter to look for in the input simulation model if the *_regional_scheme is set to regions_from_sim.
• 🤖 I have added tests, or extended existing tests, to cover any new features or bugs fixed in this PR.
• 📖 I have considered adding a new entry in CHANGELOG.md.
• 📚 I have considered updating the documentation.

[wouterjdb]

LGTM!

Don't forget to change back the test-data pointer.