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 
#include <Common/TLDListsHolder.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/logger_useful.h>
#include <IO/ReadBufferFromFile.h>
#include <IO/ReadHelpers.h>
#include <string_view>
#include <unordered_set>
namespace DB
{
namespace ErrorCodes
{
    extern const int TLD_LIST_NOT_FOUND;
    extern const int LOGICAL_ERROR;
}
TLDList::TLDList(size_t size)
    : tld_container(size)
    , pool(std::make_unique<Arena>(10 << 20))
{}
bool TLDList::insert(StringRef host)
{
    bool inserted;
    tld_container.emplace(DB::ArenaKeyHolder{host, *pool}, inserted);
    return inserted;
}
bool TLDList::has(StringRef host) const
{
    return tld_container.has(host);
}
TLDListsHolder & TLDListsHolder::getInstance()