test SQL array and UDT support

[gavinking]

Hibernate 6 introduces the @Struct and @Array annotations for mapping to SQL arrays and UDTs.

We should test this stuff. It's likely the Vert.x client doesn't support this stuff yet.

[gavinking]

So I just tested this quickly on postgres and I got:

No type mapping for org.hibernate.type.SqlTypes code: 2003 (ARRAY)

so it's indeed not working. But I'm not clear on why there's no DdlType registered or ARRAY.

[DavideD]

@gavinking Are you already working on this? Otherwise I think this is one of the issues we can have a look this week

[gavinking]

No, not working on it.

[blafond]

Pushed a couple tests around @Struct annotation: #1641

Works for DB2, PG but fails for Oracle at the moment.