After you create table with fields with dots and after alter table clickhouse throw exception about bad cast
version 20.12.3

How to reproduce

```
CREATE TABLE test_nested
(
    `id` String,
    `with_dot.str` String,
    `with_dot.array` Array(Int32)
)
ENGINE = MergeTree()
ORDER BY id


Insert Into test_nested (id,`with_dot.str`, `with_dot.array`) VALUES('123','asd',[1,2])

select * FROM test_nested


SELECT *
FROM test_nested

Query id: 42f26a6e-7573-4169-a4a1-9fe7022ba656

┌─id──┬─with_dot.str─┬─with_dot.array─┐
│ 123 │ asd          │ [1,2]          │
└─────┴──────────────┴────────────────┘

alter table test_nested ADD COLUMN `with_dot.bool` UInt8


SELECT *
FROM test_nested

Query id: 3ea8ae6b-1e0a-4ae5-b4d0-dcdcb6b7b8f8


Received exception from server (version 20.12.3):
Code: 49. DB::Exception: Received from localhost:9000. DB::Exception: Bad cast from type DB::DataTypeNumber<char8_t> to DB::DataTypeArray: (while reading from part /var/lib/clickhouse/store...
```

I think that happend because clickhouse after altert think that field `with_dot.bool` is nested and trying to cast to array, but i'm not creating nested field, i'm only use field name with `.`

ColumnPtr nested_column =
                        nested_type->createColumnConstWithDefaultValue(nested_rows)->convertToFullColumnIfConst();
                    res_columns[i] = ColumnArray::create(nested_column, offsets_column);
                }
                else
                {
                    
                    
                    res_columns[i] = type->createColumnConstWithDefaultValue(num_rows)->convertToFullColumnIfConst();
                }
            }
        }
    }
    catch (Exception & e)
    {
        
        e.addMessage("(while reading from part " + data_part->getFullPath() + ")");
        throw;
    }
}
void IMergeTreeReader::evaluateMissingDefaults(Block additional_columns, Columns & res_columns)
{
    try
    {
        size_t num_columns = columns.size();
        if (res_columns.size() != num_columns)
            throw Exception("invalid number of columns passed to MergeTreeReader::fillMissingColumns. "
                            "Expected " + toString(num_columns) + ", "
                            "got " + toString(res_columns.size()), ErrorCodes::LOGICAL_ERROR);