[Analyzer][solver][NFC] print constraints deterministically (ordered by their...

[Analyzer][solver][NFC] print constraints deterministically (ordered by their string representation)

This change is an extension to D103967 where I added dump methods for
(dis)equality classes of the State. There, the (dis)equality classes and their
contents are dumped in an ordered fashion, they are ordered based on their
string representation. This is very useful once we start to use FileCheck to
test the State dump in certain tests.

Differential Revision: https://reviews.llvm.org/D106642