**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))



QueryPlan & query_plan, const Block & source_header, const SelectQueryInfo & query_info, ContextPtr context_)
{
    Pipe pipe(std::make_shared<NullSource>(source_header));
    PrewhereInfoPtr prewhere_info_ptr = query_info.projection ? query_info.projection->prewhere_info : query_info.prewhere_info;
    if (prewhere_info_ptr)
    {
        auto & prewhere_info = *prewhere_info_ptr;
        if (prewhere_info.alias_actions)
        {
            pipe.addSimpleTransform([&](const Block & header)
            {
                return std::make_shared<ExpressionTransform>(header,
                    std::make_shared<ExpressionActions>(prewhere_info.alias_actions));
            });
        }
        if (prewhere_info.row_level_filter)
        {
            pipe.addSimpleTransform([&](const Block & header)
            {
                return std::make_shared<FilterTransform>(header,
                    std::make_shared<ExpressionActions>(prewhere_info.row_level_filter),
                    prewhere_info.row_level_column_name, true);
            });
        }
        pipe.addSimpleTransform([&](const Block & header)
        {