Java 9 compatibility

[nmervaillie]

Expected Behavior

OGM 3.0 should run under java 9
OGM jars should be automatic java modules

Current Behavior

The package org.neo4j.ogm.exception is present in core and in api modules, which is not allowed for automatic modules.
OGM is currently running under java 9 (with bolt), have to check with embedded and http.

Possible Solution

Move exceptions from the core jar to org.neo4j.ogm.exception.internal package as these ones are not supposed to be used outside of OGM.
Check and describe if/how it works in http and embedded.

Your Environment

• OGM Version used: 3.0