Blank nodes in list given invalid `.` at start in `text/n3` format.

[jeswr]

Running

import { Parser } from 'n3';
const parser = new Parser({ format: 'text/n3' });
console.log(parser.parse('<s> <p> (_:a).'))

Creates an invalid blank node id of _:.a

This also pops up in https://github.com/eyereasoner/eye-js/pull/1107/files#r1616137075

[jeswr]

Found it. In N3 mode _saveContext rescopes blank-node labels (this._prefixes._ = graph.value + '.') on every context push — including lists and blank-node property lists, not just formulae. Entering a top-level list resets the label prefix to ., so _:a becomes _:.a and no longer co-references _:a outside the list. Scoping that reassignment (and the _quantified scope, which the adjacent comment says is formula-scoped anyway) to type === 'formula' fixes it: (_:a) then yields the same _:b0_a label as elsewhere in the document, and formula-scoped labels are unchanged. Verified against bnodes in top-level lists, in formulae, and in lists nested inside formulae. Fixed in #615 — opt-in per review (formulaScopedBlankNodes); #630 tracks flipping the default next major.