HHH-17630 Test and attempted fix

[jrenaat]

https://hibernate.atlassian.net/browse/HHH-17630

[beikov]

The test errors are due to this solution wrongly assuming that if a JavaType is an enum, it can use a "default mapping" for that Java type, but note that an enum has multiple database representations: ORDINAL (tinyint, smallint, etc.) and STRING (varchar, char etc.). I didn't dig into the matter yet, but my gut guess is that the proper solution requires adaptions to the type inference in BaseSqmToSqlAstConverter to handle tuples properly.