Ensure projections can have either an order by or a group by

[mdevilliers]

The existing PROJECTION parsing failed on PROJECTIONS with just a GROUP BY

This worked

ALTER TABLE t
ADD PROJECTION p (
    SELECT x ORDER BY x
)

But not

ALTER TABLE t
ADD PROJECTION p (
    SELECT x GROUP BY x
)

This PR makes both the GROUP BY and the ORDER BY optional.

It should also deal with when both are specified even if that will fail at runtime - I suppose that is the correct behaviour for a parser and formatter.