Dbt-extractor

- Restored source distribution

- Modified ref return type to include version.

- Return type changed so that configs are a list of unmerged key-value pairs. Merging config values should now be done by the consumer.

- added parallel processing via rayon
- fixed merge logic for tags when multiple config blocks are present in one model file.

- Export `ExtractionError` to Python so it can be caught

initial release