Some URLs expect a User-Agent header.

Example (version 22.2.1.3767):
```sql
SELECT * FROM url('https://api.github.com/users/clickhouse','JSONAsString');
```
Results in:
```
Code: 86. DB::Exception: Received error from remote server /users/clickhouse. HTTP status code: 403 Forbidden, body: 
Request forbidden by administrative rules. Please make sure your request has a User-Agent header (http://developer.github.com/v3/#user-agent-required). Check https://developer.github.com for other possible causes.
: While executing URL. (RECEIVED_ERROR_FROM_REMOTE_IO_SERVER) (version 22.2.1.3767)
```

Maybe it's nice to always send a header along, something like `User-Agent: ClickHouse/22.2.1.3767` ?

size_t diff = offset_ - position;
                if (diff < settings.remote_read_min_bytes_for_seek)
                {
                    ignore(diff);
                    return offset_;
                }
            }
            if (impl)
            {
                ProfileEvents::increment(ProfileEvents::ReadBufferSeekCancelConnection);
                impl.reset();
            }
            resetWorkingBuffer();
            read_range.begin = offset_;
            read_range.end = std::nullopt;
            offset_from_begin_pos = 0;
            return offset_;
        }
        std::string getResponseCookie(const std::string & name, const std::string & def) const
        {
            for (const auto & cookie : cookies)
                if (cookie.getName() == name)
                    return cookie.getValue();
            return def;
        }
        
        
        
        
        void setNextCallback(NextCallback next_callback_)