Lower default maxNestingDepth of StreamReadConstraints / StreamWriteConstraints to 500 in 3.0

[cowtowncoder]

Currently (as of 2.17), maximum document nesting depth for both StreamReadConstraints and StreamWriteConstraints is 1,000. While this seems to work, causing no false positives (i.e. we haven't received complaints about too strict limit, it is possibly too high for some use case -- specifically for some Fuzzing systems manage to StackOverflowError before reaching limit that would avoid it.

It looks like default of 500 would solve this issue, without affecting legit use cases (probably anything above 100 would, but let's be conservative here).