* fix(tikv): improve context propagation and refactor batch delete logic
Address review comments from PR #7557:
1. Replace context.TODO() with ctx in txn.Get calls
- Fixes timeout/cancellation propagation in FindEntry
- Fixes timeout/cancellation propagation in KvGet
2. Refactor DeleteFolderChildren to use flush helper
- Eliminates code duplication
- Cleaner and more maintainable
These changes ensure proper context propagation throughout all
TiKV operations and improve code maintainability.
* error formatting
4106fc0436