**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:`

throw Exception{"Wrong argument count for function " + getName(), ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH};
            range_col = arguments[current_arguments_index].column;
            range_col_type = arguments[current_arguments_index].type;
            if (!(range_col_type->isValueRepresentedByInteger() && range_col_type->getSizeOfValueInMemory() <= sizeof(Int64)))
                throw Exception{"Illegal type " + range_col_type->getName() + " of fourth argument of function "
                        + getName() + " must be convertible to Int64.",
                    ErrorCodes::ILLEGAL_COLUMN};
            ++current_arguments_index;
        }
        Columns default_cols;
        if (dictionary_get_function_type == DictionaryGetFunctionType::getOrDefault)
        {
            if (current_arguments_index >= arguments.size())
                throw Exception{"Wrong argument count for function " + getName(), ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH};
            const auto & column_before_cast = arguments[current_arguments_index];
            if (const DataTypeTuple * type_tuple = typeid_cast<const DataTypeTuple *>(column_before_cast.type.get()))
            {
                const DataTypes & nested_types = type_tuple->getElements();
                for (const auto & nested_type : nested_types)
                    if (nested_type->isNullable())
                        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Wrong argument for function ({}) default values column nullable is not supported", getName());
            }
            else if (column_before_cast.type->isNullable())
                throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Wrong argument for function ({}) default values column nullable is not supported", getName());
            auto result_type_no_nullable = removeNullable(result_type);
            ColumnWithTypeAndName column_to_cast = {column_before_cast.column->convertToFullColumnIfConst(), column_before_cast.type, column_before_cast.name};
            auto result = castColumnAccurate(column_to_cast, result_type_no_nullable);
            if (attribute_names.size() > 1)
            {
                const auto * tuple_column = checkAndGetColumn<ColumnTuple>(result.get());