list parsing issue

[giacomociti]

a list containing a graph apparently is ignored:

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

[jeswr]

I'll try and sneak a fix into #341 since I've been fighting with other list related issues there already (in particular parsing of N3 paths within lists).