**Describe the issue**
Can't insert `String` data to column with `LowCardinality` type.

Starting from 21.1 this query fails

**How to reproduce**
```sql
CREATE TABLE default.lc_test
(   
    `id` LowCardinality(String)
)
ENGINE = MergeTree
PARTITION BY tuple()
ORDER BY id;

Ok.
0 rows in set. Elapsed: 0.003 sec.


insert into lc_test values (toString('a'));
Exception on client:
Code: 49. DB::Exception: Bad cast from type DB::ColumnString to DB::ColumnLowCardinality: data for INSERT was parsed from query

```

**Additional context**
related to issue https://github.com/DarkWanderer/ClickHouse.Client/issues/66

version 20.12 ok
TemplateStructurePtr getFromCacheOrConstruct(const DataTypePtr & result_column_type,
                                                     bool null_as_default,
                                                     TokenIterator expression_begin,
                                                     TokenIterator expression_end,
                                                     const ASTPtr & expression_,
                                                     const Context & context,
                                                     bool * found_in_cache = nullptr,
                                                     const String & salt = {});
    };
    explicit ConstantExpressionTemplate(const TemplateStructurePtr & structure_)
            : structure(structure_), columns(structure->literals.cloneEmptyColumns()) {}
    
    
    bool parseExpression(ReadBuffer & istr, const FormatSettings & format_settings, const Settings & settings);
    
    
    ColumnPtr evaluateAll(BlockMissingValues & nulls, size_t column_idx, size_t offset = 0);
    size_t rowsCount() const { return rows_count; }
private:
    bool tryParseExpression(ReadBuffer & istr, const FormatSettings & format_settings, size_t & cur_column, const Settings & settings);
    bool parseLiteralAndAssertType(ReadBuffer & istr, const IDataType * type, size_t column_idx, const Settings & settings);
private:
    TemplateStructurePtr structure;
    MutableColumns columns;
    
    size_t rows_count = 0;
};
}