fix: generate correct metadata when overflowing signed short values

[edusperoni]

Follow up of #1749

What I initally identified as some kind of circular reference is the children turned out to be the result of a wrong short -> unsigned short translation in the metadata generator.

It's impossible for the metadata generator to generate a nextSiblingId that is smaller than the actual node id. As such, this PR adds a few protections in place:

1. We fix the combination of 2 unsigned shorts into a single int
2. If we're ever close to overflowing these shorts, the metadata will error out. We should re-evaluate wheter or not we should use 32 bit numbers for this, as that increases the metadata overall size
3. When in debug mode (--log trace) we now generate a json with all the contents of the binary file.
4. If we ever get into this situation again, the runtime will log this error so the user can provide the error combined with the previously mentioned debug json for us to fix.