**Usage**
Postgres, MySQL, and Oracle support the expression `LEFT JOIN ... ON 1 = 1`, but ClickHouse does not.

It may be possible to replace `LEFT JOIN ... ON 1 = 1` with `CROSS JOIN`, but I want to use the query in the same form for lots of databases.

Please support the expression `LEFT JOIN ... ON 1 = 1`.


**Detailed SQL**
```SQL
CREATE TABLE test
(
    `name` Nullable(String),
    `id` int
)
ENGINE = Log();

insert into test values ('a', 1) ('b', 2) (null, 3);

select * from test t1 left join (select * from test ) t2 on 1 = 1   
-- DB::Exception: Not equi-join ON expression: 1 = 1. No columns in one of equality side.: While processing 1 = 1.
```

std::pair<String, String> condColumnNames() const
        {
            std::pair<String, String> res;
            if (on_filter_condition_left)
                res.first = on_filter_condition_left->getColumnName();
            if (on_filter_condition_right)
                res.second = on_filter_condition_right->getColumnName();
            return res;
        }
        size_t keysCount() const
        {
            assert(key_names_left.size() == key_names_right.size());
            return key_names_right.size();
        }
        String formatDebug() const
        {
            return fmt::format("Left keys: [{}] Right keys [{}] Condition columns: '{}', '{}'",
                               fmt::join(key_names_left, ", "), fmt::join(key_names_right, ", "),
                               condColumnNames().first, condColumnNames().second);
        }
    };
    using Clauses = std::vector<JoinOnClause>;
private:
    /** Query of the form `SELECT expr(x) AS k FROM t1 ANY LEFT JOIN (SELECT expr(x) AS k FROM t2) USING k`