[Python] Release 0.56.0

Added

• canonical.RawReason, what stopped a run from modeling a document, and RawView.reason and RawView.pointer, carrying it beside the subschema the run stopped on.

Changed

• Canonicalization of a oneOf whose branches share a region too wide to expand, which spent the document's whole intersection allowance on that choice and kept the document Raw.

Performance

• Preparing or building a schema that names no base URI parses the default one once for the process instead of once per schema.
• Canonicalization reads the facets no checker covers once per node instead of once per containment query.