**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 projection_step = std::make_unique<ExpressionStep>(query_plan.getCurrentDataStream(), expression);
    projection_step->setStepDescription("Projection");
    query_plan.addStep(std::move(projection_step));
}
void InterpreterSelectQuery::executeDistinct(QueryPlan & query_plan, bool before_order, Names columns, bool pre_distinct)
{
    auto & query = getSelectQuery();
    if (query.distinct)
    {
        const Settings & settings = context->getSettingsRef();
        auto [limit_length, limit_offset] = getLimitLengthAndOffset(query, context);
        UInt64 limit_for_distinct = 0;
        
        
        if ((!query.orderBy() || !before_order) && limit_length <= std::numeric_limits<UInt64>::max() - limit_offset)
            limit_for_distinct = limit_length + limit_offset;
        SizeLimits limits(settings.max_rows_in_distinct, settings.max_bytes_in_distinct, settings.distinct_overflow_mode);
        auto distinct_step
            = std::make_unique<DistinctStep>(query_plan.getCurrentDataStream(), limits, limit_for_distinct, columns, pre_distinct);
        if (pre_distinct)
            distinct_step->setStepDescription("Preliminary DISTINCT");
        query_plan.addStep(std::move(distinct_step));
    }
}
void InterpreterSelectQuery::executePreLimit(QueryPlan & query_plan, bool do_not_skip_offset)