Neo4j 4.X deprecated REST features used by Cypherdog

[olamotte]

First of - thanks a lot for the module, it's a really neat addition to my team's capabilities.
On a sadder note, I just updated our Neo4j backend and noticed that the HTTP endpoint and formats used by CypherDog are now "legacy".
https://neo4j.com/docs/rest-docs/current/#rest-api-cypher

• API endpoint has changed
• formatting of parameterized queries has changed too, {KEY} now has to be $KEY
• a KV mapping of parameter to value has to be shipped with a list of statements/queries
• finally results do not seem to be returned in the same way either

I have some hack right now to manipulate the content of the request made to the API endpoint, but this is not pretty. Do you already have a plan to port the module to version 4.0 of Neo4J? Happy to submit a PR as a starting point - just let me know.
Cheers