change bjdata ndarray flag to detect negative size, as part of #3475 (#3479)

* change bjdata ndarray flag to detect negative size, fix https://github.com/nlohmann/json/issues/3475

* fix CI error

* fix CI on 32bit windows

* remove platform specific out_of_range error messages

* Incorporate suggestions from @nlohmann and @falbrechtskirchinger

* fix CI errors

* add coverage

* fix sax event order

* fix coverage