[Improvement] Fine-grained shuffle manager fallback at the shuffle level

### Motivation
Now uniffle's delegation shuffle manager support fallback to sort shuffle manager in app level. We could implement it in shuffle level.

Locate the delegation shuffle manager and sort shuffle manager implementations, then trace how the existing app-level fallback is selected. Define how that fallback should instead be selected independently at the shuffle level, and verify that different shuffles can use the appropriate manager without changing unrelated behavior.

Written by the indexing model from the issue text.