Features
- Add new methods such as `filter`, `apply`, `map`, `transform` and `select` in a new `DataFrame` object to replicate some functionalities of `pandas` acting on frames containing lazily loaded data.
- Add references to saved artifacts in `DataFrame` using dedicated columns.
- Automatically load referenced artifacts in `DataFrame` using dedicated loaders from artifacts.
API Change
- Revamp `Artifact` to allow users to log custom objects by specifying new types using `register_artifact_type`.