The real exception was swallowed by another exception in CompositeJdbcConsumer::consume

### Describe the bug, including details regarding any error messages, version, and platform.

In function `CompositeJdbcConsumer::consume`, `consumer.vector.getMinorType().getType()` may throw an exception if `getType` return null. For example, `vector.getMinorType` return `DECIMAL` type but DECIMAL doesn't have get type: `DECIMAL((ArrowType)null)` (in Types.java).