IN doesn't work with parentheses

[asdine]

genji> select 1 IN (1, 2, 3);
found ,, expected ) at line 1, char 15
genji>

sqlite> select 1 IN (1, 2, 3);
1
sqlite>

Other example:

SELECT * FROM foo WHERE a IN (1, 2, 3)

This is a valid SQL expression, but currently, we only support this:

SELECT * FROM foo WHERE a IN [1, 2, 3]

This might be more complex than just parsing parentheses when we are in an IN operator.

I think we need to parse parentheses in two different ways:

Single expression: (expr)

Example:

SELECT (1);
-> 1
SELECT (1 + 1);
-> 2

This is already supported, the parser returns an expr.Parentheses expression.

List of expressions: (expr, expr, ...)

Example:

SELECT (1, 2);
-> [1, 2]
SELECT (1 + 1, 3 > 5);
-> [2, false]

If we have more than one element in that list of parentheses, this must be parsed as an expr.LiteralExprList.
There is already a function that can parse this kind of expression: https://github.com/genjidb/genji/blob/9da693665fe93d3fcfdffe3312a48712fc40023f/sql/parser/expr.go#L418:18

[asdine]

@tdakkota I have updated the issue above, let me know if you have any question

[tdakkota]

I updated PR.

Just for record:
Current fix uses look ahead parsing, it determines type of expression by next token after first expression, so I added parseListUntil function.