Neo4j plugin

We use Neo4j for some use cases at work and adding basic support for tracing Cypher queries would help us debug performance issues in the services that use them.

A Neo4j plugin for tracing queries made through `org.neo4j.driver:neo4j-java-driver` seems like it wouldn't be out of scope for this project. As far as I can tell, most options for communicating with a Neo4j server use this driver behind the scenes (our spring-data repository certainly does, out of the box anyway).

I have done some preliminary work on this and I got a plugin to work with our APM (7.4). I can see the traces correctly reported with some metadata attached.

I'm willing to submit a PR (though the code still needs some work) and I have also gotten a verbal agreement from my CTO regarding the CLA. Is this something that would be of interest to you?