fix: clustering_information panic if string domain is none

[zhyass]

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Summary

The cause of this panic is that the default domain maximum for String types is NULL. Therefore, wrapping the String type in a Nullable is necessary to handle this correctly.

• fixes: #16763

Tests

• [ ] Unit Test
• [x] Logic Test
• [ ] Benchmark Test
• [ ] No Test - Explain why

Type of change

• [x] Bug Fix (non-breaking change which fixes an issue)
• [ ] New Feature (non-breaking change which adds functionality)
• [ ] Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• [ ] Documentation Update
• [ ] Refactoring
• [ ] Performance Improvement
• [ ] Other (please describe):

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This change is 

[dantengsky]

@zhyass

LGTM, besides: seems you are using a different version of py code formatter black ?