Fix typings for `Cypher.and` and `Cypher.or`

[angrykoala]

Currently, Cypher.and and Cypher.or typings may lie, as an array of predicates may result in undefined.

For example:

const predicates: Cypher.Predicate[] = [];

const andPredicate = Cypher.and(...predicates); // andPredicate is undefined, yet its type is "Predicate"