Add pub query

[dosumis]

3 sources of pubs:

1. Curation of expression:

MATCH p=(n:Cell)<-[:INSTANCEOF]-()-[r:part_of]->() 
OPTIONAL MATCH (pub:pub) where pub.short_form = r.pub 
RETURN pub.label, n.label limit 100

2. NLP

MATCH p=()-[r:has_reference]->() WHERE r.typ = ['nlp'] RETURN p LIMIT 25

3. Ontology

MATCH p=()-[r:has_reference]->() WHERE r.typ = 'def' or r.typ  = 'syn' RETURN p LIMIT 25

Query should combine all 3 sources and have a column to distinguish between them.

Query should be on site an on VFB_connect

[dosumis]

Note - there is an issue with inconsistency of pub edges that should be fixed.

3 sources of these links:

1. kb - kb2 all attributes should be lists
2. side loading by https://github.com/VirtualFlyBrain/VFB_neo4j/blob/master/src/uk/ac/ebi/vfb/neo4j/flybase2neo/expression_runner.py - or something it calls
3. NLP pipeline.

These should all be made into lists and all code that depends on this should expect lists (side loading and queries).

(related issue - review code for dealing with synonym and def refs on ontology terms)