Writing out a list of encoded entries

The list encoder listEncFn and the loop behind it moved to Complexitylib.Classes.P.Range, where listEncFn_mem_FP needs no bound on the loop's state, and to its internals Complexitylib.Classes.P.Range.Internal, which keep listStep, entryCat, listStep_iterate, listEncFn_eq and bitstringEncode_of_entries under their old names. This module re-exports both, together with Complexitylib.Classes.PCP.Internal.NatEncode, so that its importers see the same names as before.