**Describe what's wrong**

Query with rollup using same selected field name as the name of underlying column reports structure mismatch

**Does it reproduce on recent release?**

yes

**How to reproduce**

`21.9.2.17`

```sql
CREATE TABLE test
(
    `d` DateTime,
    `a` LowCardinality(String),
    `b` UInt64
)
ENGINE = MergeTree
PARTITION BY toDate(d)
ORDER BY d;

SELECT *
FROM (
    SELECT
        a,
        max((d, b)).2 AS value
    FROM test
    GROUP BY rollup(a)
)
WHERE a <> '';
```

**Expected behavior**

This used to return an ok result on v21.8

**Error message and/or stacktrace**

> Code: 352. DB::Exception: Block structure mismatch in (columns with identical name must have identical structure) stream: different columns:
> notEquals(a, '') LowCardinality(UInt8) ColumnLowCardinality(size = 0, UInt8(size = 0), ColumnUnique(size = 1, UInt8(size = 1)))
> notEquals(a, '') LowCardinality(UInt8) Const(size = 0, ColumnLowCardinality(size = 1, UInt8(size = 1), ColumnUnique(size = 2, UInt8(size = 2)))). (AMBIGUOUS_COLUMN_NAME) (version 21.9.2.17 (official build))



*  - therefore, we merge the sorted streams from remote servers.
                  *
                  * Also in case of remote servers was process the query up to WithMergeableStateAfterAggregationAndLimit
                  * (distributed_group_by_no_merge=2 or optimize_distributed_group_by_sharding_key=1 takes place),
                  * then merge the sorted streams is enough, since remote servers already did full ORDER BY.
                  */
                if (from_aggregation_stage)
                    executeMergeSorted(query_plan, "after aggregation stage for ORDER BY");
                else if (!expressions.first_stage
                    && !expressions.need_aggregate
                    && !expressions.has_window
                    && !(query.group_by_with_totals && !aggregate_final))
                    executeMergeSorted(query_plan, "for ORDER BY, without aggregation");
                else    
                    executeOrder(
                        query_plan,
                        query_info.input_order_info ? query_info.input_order_info
                                                    : (query_info.projection ? query_info.projection->input_order_info : nullptr));
            }
            /** Optimization - if there are several sources and there is LIMIT, then first apply the preliminary LIMIT,
              * limiting the number of rows in each up to `offset + limit`.
              */
            bool has_withfill = false;
            if (query.orderBy())
            {
                SortDescription order_descr = getSortDescription(query, context);
                for (auto & desc : order_descr)
                    if (desc.with_fill)
                    {
                        has_withfill = true;