Detect (and flag) if a rule has ambiguous molecularity #235
Description
When specifying a rule, one can write a LHS with two components that have no connection stated in that LHS. Depending on the model, those components might be already connected (e.g. through a third party). In such a case, the physical interpretation of the model would require the usage of a different rate constant, as the diffusion volume of connected components usually is much smaller than the one of disconnected ones.
It would be useful if the IDE could flag cases where the LHS might have such ambiguous molecularity (e.g. by checking the contact map). Full reachability analysis of the species space seems too costly, but just verifying through the contact map would suggest rules to re-check. Since this is not a sensa stricta error, these rules would just be flagged for revision (i.e. instead of 'warning', maybe just 'hint' ?).