Return `NativeType` instead of `DataType` for `get_example_types`

### Is your feature request related to a problem or challenge?

`get_example_types` is used to list possible types for a function in information schema

Instead of DataType, NativeType is enough, we don't need to care about the exact DataType.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

Maybe we need TypeClass to represent set of NativeType similar to TypeSignatureClass?

### Additional context

_No response_