22.2.1.4422.

```
create table test_alias (K Int64, D Date, S String, B Int64 Alias length(S)) Engine=MergeTree order by K;
insert into test_alias select number, today(), 'sdfsdfsdfsdfsdfds' from numbers(10000000);

session1: 
clickhouse-benchmark -c 10 <<< "insert into test_alias select number, today(), 'sdfsdfsdfsdfsdfds' from numbers(10000)"

session2: 
alter table test_alias drop column B;
0 rows in set. Elapsed: 251.043 sec.
```

especially it can be a problem with S3 disks

Alias columns do not persist in parts even in columns.txt
{
    return type == MODIFY_SETTING || type == RESET_SETTING;
}
bool AlterCommand::isRequireMutationStage(const StorageInMemoryMetadata & metadata) const
{
    if (ignore)
        return false;
    
    if (isRemovingProperty() || type == REMOVE_TTL || type == REMOVE_SAMPLE_BY)
        return false;
    if (type == DROP_COLUMN || type == DROP_INDEX || type == DROP_PROJECTION || type == RENAME_COLUMN)
        return true;
    if (type != MODIFY_COLUMN || data_type == nullptr)
        return false;
    for (const auto & column : metadata.columns.getAllPhysical())
    {
        if (column.name == column_name && !isMetadataOnlyConversion(column.type.get(), data_type.get()))
            return true;
    }
    return false;
}
bool AlterCommand::isCommentAlter() const