**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))



{
    auto & query = getSelectQuery();
    if (!query.limitByLength() || !query.limitBy())
        return;
    Names columns;
    for (const auto & elem : query.limitBy()->children)
        columns.emplace_back(elem->getColumnName());
    UInt64 length = getLimitUIntValue(query.limitByLength(), context, "LIMIT");
    UInt64 offset = (query.limitByOffset() ? getLimitUIntValue(query.limitByOffset(), context, "OFFSET") : 0);
    auto limit_by = std::make_unique<LimitByStep>(query_plan.getCurrentDataStream(), length, offset, columns);
    query_plan.addStep(std::move(limit_by));
}
void InterpreterSelectQuery::executeWithFill(QueryPlan & query_plan)