[Feature] support neo4j backend of dataprep/retriever in helm chart

[lianhao]

Priority

Undecided

OS type

Ubuntu

Hardware type

Xeon-GNR

Running nodes

Single Node

Description

We need to support neo4j vector DB backend in the following helm charts:

• data-prep
• retriever-usvc

Background information:

• https://github.com/opea-project/GenAIComps/tree/main/comps/third_parties/neo4j
• https://github.com/opea-project/GenAIComps/blob/main/comps/dataprep/src/README_neo4j_llamaindex.md
• https://github.com/opea-project/GenAIComps/blob/main/comps/retrievers/src/README_neo4j.md