**Describe the unexpected behaviour**
ClickHouse returns exception if you would try to read polygon dictionary via SELECT query.

**How to reproduce**
ClickHouse version 21.10


```
CREATE DICTIONARY polygon_dict (
    key Array(Array(Array(Array(Float64)))),
    name String,
    value UInt64
)
PRIMARY KEY key
LAYOUT(POLYGON())
SOURCE(CLICKHOUSE(table 'polygon_dict_src'))
LIFETIME(MIN 300 MAX 360);

CREATE TABLE polygon_dict_src
(
    `key` Array(Array(Array(Array(Float64)))),
    `name` String,
    `value` UInt64
)
ENGINE = Log
	
INSERT INTO polygon_dict_src SELECT [[[[1.1,2.1],[5,3],[6,4],[1,4]]]], 'some', 10;


CREATE DICTIONARY polygon_dict (
    key Array(Array(Array(Array(Float64)))),
    name String,
    value UInt64
)
PRIMARY KEY key
LAYOUT(POLYGON())
SOURCE(CLICKHOUSE(table 'polygon_dict_src'))
LIFETIME(MIN 300 MAX 360);

SELECT dictGet(polygon_dict, 'name', (2., 3.)) AS x

┌─x────┐
│ some │
└──────┘

SELECT *
FROM polygon_dict

0 rows in set. Elapsed: 0.008 sec.

Received exception from server (version 21.10.1):
Code: 1. DB::Exception: Received from localhost:9000. DB::Exception: Reading the dictionary is not allowed. (UNSUPPORTED_METHOD)
```


**Expected behavior**
It's allowed to read POLYGON dictionaries via SELECT query.

size_t getBytesAllocated() const override { return bytes_allocated; }
    size_t getQueryCount() const override { return query_count.load(std::memory_order_relaxed); }
    double getFoundRate() const override
    {
        size_t queries = query_count.load(std::memory_order_relaxed);
        if (!queries)
            return 0;
        return static_cast<double>(found_count.load(std::memory_order_relaxed)) / queries;
    }
    double getHitRate() const override { return 1.0; }
    size_t getElementCount() const override { return attributes.empty() ? 0 : attributes.front()->size(); }
    double getLoadFactor() const override { return 1.0; }
    const IDictionarySource * getSource() const override { return source_ptr.get(); }
    const DictionaryStructure & getStructure() const override { return dict_struct; }
    const DictionaryLifetime  & getLifetime() const override { return dict_lifetime; }
    bool isInjective(const std::string & attribute_name) const override { return dict_struct.getAttribute(attribute_name).injective; }
    DictionaryKeyType getKeyType() const override { return DictionaryKeyType::Complex; }
    ColumnPtr getColumn(
        const std::string& attribute_name,
        const DataTypePtr & result_type,