Is your feature request related to a problem or challenge?

Currently, DataFusion's handling of SQL dialects lacks type safety and clarity

Describe the solution you'd like

Introduce a strongly-typed Dialect enum that explicitly defines all supported SQL dialects in DataFusion

Describe alternatives you've considered

• constants: better than raw strings but still doesn't provide the same level of type safety as an enum
• trait-based approach: more flexible but adds unnecessary complexity for this use case

Additional context

No response