For [the rule in the list](https://github.com/ClickHouse/ClickHouse/blob/82fc7375dd3ac4faae6c3b0db9f3a28fb2802d05/tests/config/top_level_domains/public_suffix_list.dat#L6430) `*.sch.uk` 

and domain like `www.something.sheffield.sch.uk`  the correct / expected result is `sheffield.sch.uk`

Example with python (correct)

```
-- pip install publicsuffix2
-- python3
>>> from publicsuffix2 import get_public_suffix
>>> get_public_suffix('www.something.sheffield.sch.uk')
'something.sheffield.sch.uk'
```

Same from clickhouse:
```
SELECT cutToFirstSignificantSubdomain('www.something.sheffield.sch.uk')

Query id: 9661461f-a393-43ea-97a1-47c0a8850515

┌─cutToFirstSignificantSubdomain('www.something.sheffield.sch.uk')─┐
│ sch.uk                                                           │
└──────────────────────────────────────────────────────────────────┘
```

/cc @azat 
{
public:
    using Map = std::unordered_map<std::string, TLDList>;
    static TLDListsHolder & getInstance();
    
    
    void parseConfig(const std::string & top_level_domains_path, const Poco::Util::AbstractConfiguration & config);
    
    
    
    
    
    
    
    size_t parseAndAddTldList(const std::string & name, const std::string & path);
    
    const TLDList & getTldList(const std::string & name);
protected:
    TLDListsHolder();
    std::mutex tld_lists_map_mutex;
    Map tld_lists_map TSA_GUARDED_BY(tld_lists_map_mutex);
};
}