Merge category and functor deduction scripts

[ScriptRaccoon]

• Fix outdated functor deduction logic by aligning it with the category BFS algorithm (Use BFS for deductions + Refactor #174)
• Reduce duplication between categories and functors (only a few schema-specific parts remain separate)
• Ensure future algorithm changes apply to both structures automatically
• Provide a foundation for extending the same deduction logic to other categorical structures (Add support for other categorical structures #4)
• Add tests for functors (similar to the category tests) ensuring that selected functors have all properties decided
• Remove "category" as default value from Svelte components