Pl/localization

[paulflang]

The PR shows examples for modeling

• subcellular compartmens/localization.
• dependencies/environments that are required for rules to fire.

Future directions (currently deprioritized) include:

• localization:
  • disallowing tensoring of compartments (e.g. there is no proper meaning for $\mathrm{Nucleus \otimes Nucleus}$).
  • providing cBNG-like description of nesting of compartments (e.g. see Section 7 here), incl tying compartments to numeric values describing their volume.
• environments:
  • letting rules fire if the environment is satisfied no by model declaration, but by a model producing all required dependencies.