**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.

{
    const auto rows = block.rows();
    size_t skip_key_column_offset = 1;
    for (size_t i = 0; i < attributes.size(); ++i)
    {
        const auto & block_column = block.safeGetByPosition(i + skip_key_column_offset);
        const auto & column = block_column.column;
        attributes[i]->assumeMutable()->insertRangeFrom(*column, 0, column->size());
    }
    
    polygons.reserve(polygons.size() + rows);
    polygon_index_to_attribute_value_index.reserve(polygon_index_to_attribute_value_index.size() + rows);
    const auto & key = block.safeGetByPosition(0).column;
    extractPolygons(key);
}
void IPolygonDictionary::loadData()
{
    QueryPipeline pipeline(source_ptr->loadAll());
    PullingPipelineExecutor executor(pipeline);
    Block block;
    while (executor.pull(block))
        blockToAttributes(block);
    
    PaddedPODArray<double> areas;
    areas.resize_fill(polygons.size());
    std::vector<std::pair<Polygon, size_t>> polygon_ids;
    polygon_ids.reserve(polygons.size());