DEFAULT_MAX_DESCENDANT_DEPTH

Descendant depth allowed by default: one hundred thousand.

Deliberately above JsonPathQueryTest's 20 000-deep fixture, which exists to prove the walk is iterative and would be a strange thing to then forbid. Depth is the weakest of the three bounds — a document's depth is already bounded by the memory it took to build — and it is here because the location of a node is a chain that long.