OGM-572 Remove neo4j-cypher-dsl dependency

https://hibernate.atlassian.net/browse/OGM-572
I was contemplating whether this hierarchy of `*Expression` shouldn't be merged with `*Predicate` (there seems to be the same type of node in both models), but then I guess we'll switch to the "real" Cypher DSL once it's properly available, so it's probably not worth to put more effort into this interim solution?