functions to match rules by local node fanin/fanout, and related queries
some refactoring of useful functions
initialize and maintain an is_atomic field in unique_process_graph's faninout_struct_type
this is redundant, but avoids having to lookup atomicity in the global node array
prsim: functions/commands to query type-local rules that match from->to[dir]
this will be needed to alter properties of rules like after_min/max