**Describe the unexpected behaviour**
If Null being passed as dictionary key, dictGetOrDefault returns null instead of default value.

**How to reproduce**
Clickhouse version 21.5, 21.1, 20.8

```

CREATE VIEW dict_null_source AS SELECT 1 as key, 1 as val;
CREATE DICTIONARY dict_null (key UInt64, val UInt32) PRIMARY KEY key SOURCE(CLICKHOUSE(host 'localhost' user 'default' table 'dict_null_source' ))LAYOUT(FLAT)LIFETIME(300)


SELECT dictGetOrDefault('default.dict_null', 'val', CAST(NULL, 'Nullable(UInt64)'), 0) AS val

Query id: 79518a8e-b439-4d08-a0b2-85e4b3ef99eb

┌──val─┐
│ ᴺᵁᴸᴸ │
└──────┘
```

**Additional context**
```

SELECT dictGetOrDefault('default.dict_null', 'val', CAST(1, 'UInt64'))

Query id: 71ec76a1-fb61-4641-9145-79c6bfffd490


0 rows in set. Elapsed: 0.001 sec.

Received exception from server (version 21.5.1):
Code: 42. DB::Exception: Received from localhost:9000. DB::Exception: Wrong argument count for function dictGetOrDefault: While processing dictGetOrDefault('default.dict_null', 'val', CAST(1, 'UInt64')).

```

Error message in 21.1 was better:  `Number of arguments for function dictGetOrDefault doesn't match: passed 3, should be 4:`

auto dictionary_get_result_column_mutable = dictionary_get_result_column->assumeMutable();
        if (result_data_type.isTuple())
        {
            ColumnTuple & column_tuple = assert_cast<ColumnTuple &>(*dictionary_get_result_column_mutable);
            const auto & columns = column_tuple.getColumns();
            size_t tuple_size = columns.size();
            MutableColumns new_columns(tuple_size);
            for (size_t tuple_column_index = 0; tuple_column_index < tuple_size; ++tuple_column_index)
            {
                auto nullable_column_map = ColumnVector<UInt8>::create();
                auto & nullable_column_map_data = nullable_column_map->getData();
                nullable_column_map_data.assign(is_key_in_dictionary_data);
                auto mutable_column = columns[tuple_column_index]->assumeMutable();
                if (ColumnNullable * nullable_column = typeid_cast<ColumnNullable *>(mutable_column.get()))
                {
                    auto & null_map_data = nullable_column->getNullMapData();
                    addNullMap(null_map_data, is_key_in_dictionary_data);
                    new_columns[tuple_column_index] = std::move(mutable_column);
                }
                else
                    new_columns[tuple_column_index] = ColumnNullable::create(std::move(mutable_column), std::move(nullable_column_map));
            }
            result = ColumnTuple::create(std::move(new_columns));
        }
        else
        {
            if (ColumnNullable * nullable_column = typeid_cast<ColumnNullable *>(dictionary_get_result_column_mutable.get()))
            {
                auto & null_map_data = nullable_column->getNullMapData();
                addNullMap(null_map_data, is_key_in_dictionary_data);