Looks like https://github.com/ClickHouse/ClickHouse/pull/21303 is broke also "clear column" for such columns.

How to reproduce:

```
CREATE TABLE test.TTAdmLog
(
    `ts` DateTime,
    `event_date` Date DEFAULT toDate(ts),
    `impression_id` String DEFAULT '',
    `creative_id` String DEFAULT '',
    `creative_adm` String DEFAULT '',
    `impression_id_compressed` FixedString(16) DEFAULT UUIDStringToNum(impression_id),
    `impression_id_hashed` UInt16 DEFAULT reinterpretAsUInt16(impression_id_compressed),
)
ENGINE = ReplicatedMergeTree('/clickhouse/tables/{shard}/TTAdmLogTest', '{replica}')
PARTITION BY toMonday(event_date)
ORDER BY (event_date, impression_id_hashed)
SAMPLE BY impression_id_hashed
SETTINGS replicated_deduplication_window = 1000, replicated_deduplication_window_seconds = 864000, index_granularity = 8192

CREATE MATERIALIZED VIEW test.TTView
(
    `event_date` Date,
    `creative_id` String,
    `creative_adm` AggregateFunction(anyLast, String),
)
ENGINE = ReplicatedAggregatingMergeTree('/clickhouse/tables/{shard}/TTViewTest', '{replica}', event_date, (event_date, creative_id), 8192) AS
SELECT 
    toStartOfMonth(event_date) AS event_date,
    arrayJoin(splitByChar(',', creative_id)) AS creative_id,
    anyLastState(creative_adm) AS creative_adm,
FROM test.TTAdmLog
GROUP BY 
    event_date,
    creative_id,

```


ClickHouse server version 20.9.3 revision 54439.

```
alter table test.TTAdmLog clear column creative_adm in partition '2021-03-22'

OK

```
ClickHouse server version 21.4.3 revision 54447.

```
alter table test.TTAdmLog  clear column creative_adm in partition '2021-03-22'

DB::Exception: Trying to ALTER DROP column creative_adm which is referenced by materialized view ['TTView'].

```

insertIntoBuffer(block, *least_busy_buffer);
        least_busy_lock.unlock();
        storage.reschedule();
    }
private:
    StorageBuffer & storage;
    StorageMetadataPtr metadata_snapshot;
    void insertIntoBuffer(const Block & block, StorageBuffer::Buffer & buffer)
    {
        time_t current_time = time(nullptr);
        
        Block sorted_block = block.sortColumns();
        if (!buffer.data)
        {
            buffer.data = sorted_block.cloneEmpty();
        }
        else if (storage.checkThresholds(buffer, true, current_time, sorted_block.rows(), sorted_block.bytes()))
        {
            /** If, after inserting the buffer, the constraints are exceeded, then we will reset the buffer.
              * This also protects against unlimited consumption of RAM, since if it is impossible to write to the table,
              *  an exception will be thrown, and new data will not be added to the buffer.
              */
            storage.flushBuffer(buffer, false , true );
        }
        if (!buffer.first_write_time)
            buffer.first_write_time = current_time;
        appendBlock(sorted_block, buffer.data);
    }
};
BlockOutputStreamPtr StorageBuffer::write(const ASTPtr & , const StorageMetadataPtr & metadata_snapshot, ContextPtr )