Implement N-Triples Parsing and Serialization

[bivens-dev]

Description

This issue tracks the implementation of N-Triples parsing and serialization capabilities within the rdf_dart package. N-Triples is a simple, line-based format for encoding RDF graphs, and its implementation will enable the rdf_dart package to interoperate with other RDF tools and systems that support this format.

Goal

The goal of this issue is to implement:

• An N-Triples parser that can read a stream of N-Triples and produce a corresponding set of Triple objects.
• An N-Triples serializer that can write a collection of Triple objects to a stream in N-Triples format.

Implementation Notes

• Refer to the N-Triples specification (https://www.w3.org/TR/n-triples/) for the exact syntax rules.
• Leverage the dart:convert package for encoding and decoding interfaces.
• Use the existing IRI class for representing IRIs.
• Consider using a dedicated exception class for N-Triples parsing errors (e.g., NTriplesParseException).
• Use the W3C N-Triples Test Cases to validate the implementation.