Validate data against a schema

Changes for 0.579 - 2024-01-15T03:32:27Z

• improve performance by checking for duplicates by comparing the checksum of a schema rather than the content itself
• fix error occurring when using the FormatAssertion vocabulary in an evaluator object that was loaded from a serialized object
• fixed custom format definitions to not allow 'integer' types, as per the specification
• support custom format definitions that operate on more than one core data type
• fixed handling of unrecognized formats in draft2020-12 and later (but only when the FormatAssertion vocabulary is explicitly requested, not with validate_formats=1)
• the format keyword now respects the "stringy_numbers" option