**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.
```

{
    ASTPtr keys_list = std::make_shared<ASTExpressionList>();
    keys_list->children = key_asts_left;
    for (const auto & clause : clauses)
    {
        if (clause.on_filter_condition_left)
            keys_list->children.push_back(clause.on_filter_condition_left);
    }
    return keys_list;
}
ASTPtr TableJoin::rightKeysList() const
{
    ASTPtr keys_list = std::make_shared<ASTExpressionList>();
    if (hasOn())
        keys_list->children = key_asts_right;
    for (const auto & clause : clauses)
    {
        if (clause.on_filter_condition_right)
            keys_list->children.push_back(clause.on_filter_condition_right);
    }
    return keys_list;
}
Names TableJoin::requiredJoinedNames() const