Use the Neptune Analytics schema API when available

Discovering schema shape can be an expensive operation on larger databases. Neptune Analytics provides an API that provides all or nearly all of the information needed for schema discovery. This can greatly improve the performance of the schema sync process.

## Related Issues

- [AWS documentation on Neptune Analytics schema API](https://docs.aws.amazon.com/neptune-analytics/latest/userguide/custom-algorithms-property-graph-schema.html)