…g in Querydsl Aggregations (#1181)

* Introduce TypeWrapper to wrap Expression results into custom types

- Implement TypeWrapper<S, T> as a FactoryExpression
- Allows converting a source Expression (e.g. BigDecimal) to a domain type (e.g. Money)
- Prepares QueryDSL core to support custom aggregation projections without core API changes

* Add JPAQueryCustomTypeWrapperTest covering success and failure scenarios

- Verify IllegalArgumentException for unsupported custom types without wrapper
- Verify sum-and-wrap to Money via TypeWrapper in both direct and DTO projection use cases
- Ensure both positive and negative paths are exercised