Performance of ORDER BY on sorting key prefix with braces is 2x slower than without due to inefficient execution plan.
Without braces:
```sql
EXPLAIN PIPELINE
SELECT
    CounterID,
    EventDate
FROM hits_v1
ORDER BY
    CounterID ASC,
    EventDate ASC

┌─explain───────────────────────────┐
│ (Expression)                      │
│ ExpressionTransform               │
│   (Sorting)                       │
│   MergingSortedTransform 19 → 1   │
│     (Expression)                  │
│     ExpressionTransform × 19      │
│       (ReadFromMergeTree)         │
│       MergeTreeInOrder × 19 0 → 1 │
└───────────────────────────────────┘
```
With braces:
```sql
EXPLAIN PIPELINE
SELECT
    CounterID,
    EventDate
FROM hits_v1
ORDER BY (CounterID, EventDate) ASC

┌─explain────────────────────────────────┐
│ (Expression)                           │
│ ExpressionTransform                    │
│   (Sorting)                            │
│   MergingSortedTransform 16 → 1        │
│     MergeSortingTransform × 16         │
│       LimitsCheckingTransform × 16     │
│         PartialSortingTransform × 16   │
│           (Expression)                 │
│           ExpressionTransform × 16     │
│             (ReadFromMergeTree)        │
│             MergeTreeThread × 16 0 → 1 │
└────────────────────────────────────────┘
```
}
    has_virtual_shard_num = false;
    
    
    if (storage)
    {
        const auto storage_virtuals = storage->getVirtuals();
        for (auto it = unknown_required_source_columns.begin(); it != unknown_required_source_columns.end();)
        {
            auto column = storage_virtuals.tryGetByName(*it);
            if (column)
            {
                source_columns.push_back(*column);
                it = unknown_required_source_columns.erase(it);
            }
            else
                ++it;
        }
        if (is_remote_storage)
        {
            for (const auto & name_type : storage_virtuals)
            {
                if (name_type.name == "_shard_num" && storage->isVirtualColumn("_shard_num", storage_snapshot->getMetadataForQuery()))
                {
                    has_virtual_shard_num = true;
                    break;
                }
            }
        }
    }