Add Jelly format support (RDF serialization)

[lapkinvladimir]

This PR adds support for using the Jelly RDF serialization format in kglab

Jelly is a binary RDF format integrated with RDFLib via the pyjelly library.
It provides faster load/save performance for large RDF graphs compared to text-based formats such as Turtle or N-Triples.

What was done

• Added "jelly" as a supported RDF format in serde.py
• Added pyjelly[rdflib] as a dependency so Jelly can be used through RDFLib

Implemented a small test suite covering:

• basic save/load roundtrip
• SPARQL querying after Jelly load
• wildcard loading of multiple .jelly files
• Measure() behavior after Jelly load

All existing behavior for other formats remains unchanged

[ceteri]

Thank you @lapkinvladimir !!

We've made lots of updates recently to get up to speed with recent Py versions and also updates within RDFlib. Trying to align these now.

[ceteri]

Our latest main branch has an updated pyproject.toml and we're getting merge conflicts with this PR which would be simpler to fix in your fork.

We have added the pyjelly[rdflib] dependency in advance.

Could you please update to the latest pyproject.toml ? Then the PR should merge fine.

[lapkinvladimir]

@ceteri Hi! I’ve aligned pyproject.toml exactly with main as requested

[ceteri]

Outstanding! Many thanks @lapkinvladimir :)