"Dump" command - Add functionality similar to binary2text "-largebinaryhashonly"

When using dump command to compare serialized files it can be useful to summarize large arrays with a hash.

Currently dump does have "--skip-large-arrays" but the binary2text -largebinaryhashonly option seems better because it can work when doing diffs of dumps to look for object change.s

[#32] Summarize large arrays with a hash in dump output by default (#113