strict equality of complexes

[mahrud]

I closed my earlier issue because the issue is in using === for complexes, not truncation itself:

i1 : R = QQ[x];

i2 : complex R === complex R

o2 = false

This is because Complex inherits from mutable hash table, and there isn't another === method installed.

So perhaps really the issue is using === or =!= for complexes, for instance in liftMapAlongQuasiIsomorphism: https://github.com/Macaulay2/M2/blob/a816bf9a79201423e49991615b19cecfff9ed4a9/M2/Macaulay2/packages/Complexes/ChainComplexMap.m2#L1279