Test and integrate oneDAL

GPU (integrated / discrete) support for NN search, DBSCAN and connected components.
Potentially faster on CPU.

Use v2023.x since v2024 onwards does not support macOS.

Potentially faster:
- nearest neighbor search: Compare nanoflann vs oneDAL-kNN
- DBSCAN 
- connected components

Links:
- https://github.com/oneapi-src/oneDAL