This allows additional data roundtripping through JSON since to_json() already
supports tables. There are some subtleties around the formatting of strings in
JSON object keys, for which this adds a bit of helper infrastructure.
This also expands the language.table test to verify the roundtrips, and adapts
bif.from_json to include a table in the test record.
When a JSON document contains key names containing colons or other
special characters that are not valid in Zeek identifiers, from_json()
cannot be used to parse such input.
This change allows a customizable normalization function.
Closes#3142.
* amazing-pp/topic/fupeng/from_json_bif:
Implement from_json bif
Minor updates during merge: Moved ValFromJSON into zeek::detail for the
time being, removed gotos, normalized some error messages to lower case,
minimal test extension and added a raw reader input framework test reading
"json lines" as a demo, adding notes about the implicit type
conversions.
