add elementID in apoc.convert.toTree output as key-value pair (`_elementId`)

[dorn-gerhard]

Feature description (Mandatory)

As the use of ID is not recommended and instead elementId should be used in future it would be convenient to have an additional key-value pair _elementId in the output of the apoc.convert.toTree method.

In addition it would be convenient to make _id, _elementId and _type suppressable via the config: { nodes: {'Labelname': ['-_id', ...]}}

Considered alternatives

Alternatives would be to work with ID or to add a unique ID to all nodes.

[gem-neo4j]

Hi! Thank you for writing in, I have added this suggestion to our work on migrating APOC to be more elementId friendly