Add Quoted Triples and Annotation syntax from CG report

[gkellogg]

This can wait for semantics decisions before adding Annotation syntax, but we should probably get quoted triples in to align with N-Triples/N-Quads.

[domel]

Agree, especially since sparql-query already has such PR.

[afs]

We can use the SPARQL grammar as a single place to agree on rule naming and rule order then replicate that for consistency.

I agree that annotation syntax is "unclear" - both UCR and semantics will have input.

Annotation syntax is in w3c/sparql-query#78 without any opinion attached. It is a bit easier to do all once, now then remove later than it is to two design steps when the second step may uncover issues with the first.

Online validator: https://www.sparql.org/query-validator.html

Jena does have an internal Turtle parser based on a generated grammar that can be updated to aligned to the query PR, if that helps.