**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))



static void executeExpression(QueryPlan & query_plan, const ActionsDAGPtr & expression, const std::string & description);
    
    void executeWindow(QueryPlan & query_plan);
    void executeOrder(QueryPlan & query_plan, InputOrderInfoPtr sorting_info);
    void executeOrderOptimized(QueryPlan & query_plan, InputOrderInfoPtr sorting_info, UInt64 limit, SortDescription & output_order_descr);
    void executeWithFill(QueryPlan & query_plan);
    void executeMergeSorted(QueryPlan & query_plan, const std::string & description);
    void executePreLimit(QueryPlan & query_plan, bool do_not_skip_offset);
    void executeLimitBy(QueryPlan & query_plan);
    void executeLimit(QueryPlan & query_plan);
    void executeOffset(QueryPlan & query_plan);
    static void executeProjection(QueryPlan & query_plan, const ActionsDAGPtr & expression);
    void executeDistinct(QueryPlan & query_plan, bool before_order, Names columns, bool pre_distinct);
    void executeExtremes(QueryPlan & query_plan);
    void executeSubqueriesInSetsAndJoins(QueryPlan & query_plan, std::unordered_map<String, SubqueryForSet> & subqueries_for_sets);
    void
    executeMergeSorted(QueryPlan & query_plan, const SortDescription & sort_description, UInt64 limit, const std::string & description);
    String generateFilterActions(ActionsDAGPtr & actions, const Names & prerequisite_columns = {}) const;
    enum class Modificator
    {
        ROLLUP = 0,
        CUBE = 1
    };
    void executeRollupOrCube(QueryPlan & query_plan, Modificator modificator);
    /** If there is a SETTINGS section in the SELECT query, then apply settings from it.
      *
      * Section SETTINGS - settings for a specific query.
      * Normally, the settings can be passed in other ways, not inside the query.
      * But the use of this section is justified if you need to set the settings for one subquery.
      */