OGM-642 Avoiding read prior to insert if possible

Adding new method `getDuplicateInsertPreventionStrategy()`on `GridDialect`. By default, we do the explicit look-up as before, but of the store itself can detect the situation, we rely on that and omit the additional read.
Why should this be a new form of exception?
Isn't there a well defined exception type in JPA (i.e. created from the existing JPA code) ?