**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.

{
        dest.emplace_back();
        ids.push_back((ids.empty() ? 0 : ids.back() + new_multi_polygon));
    }
    void addPoint(IPolygonDictionary::Coord x, IPolygonDictionary::Coord y)
    {
        auto & last_polygon = dest.back();
        auto & last_ring = (last_polygon.inners().empty() ? last_polygon.outer() : last_polygon.inners().back());
        last_ring.emplace_back(x, y);
    }
};
void addNewPoint(IPolygonDictionary::Coord x, IPolygonDictionary::Coord y, Data & data, Offset & offset)
{
    if (offset.atLastPointOfRing())
    {
        if (offset.atLastRingOfPolygon())
            data.addPolygon(offset.atLastPolygonOfMultiPolygon());
        else
        {
            /** An outer ring is added automatically with a new polygon, thus we need the else statement here.
             *  This also implies that if we are at this point we have to add an inner ring.
             */
            auto & last_polygon = data.dest.back();
            last_polygon.inners().emplace_back();
        }
    }
    data.addPoint(x, y);
    ++offset;
}
const IColumn * unrollMultiPolygons(const ColumnPtr & column, Offset & offset)