Fix ORDER BY arg parsing in sqlite

[andriygm]

sqlc currently doesn't handle bound ORDER BY clauses in sqlite, nor does it have tests for this behavior. This PR attempts for rectify this. Closes #3788.

[andriygm]

currently, base behavior works but mixing params like so:

-- name: ListAuthorsColumnSortDirection :many
SELECT * FROM authors
WHERE id > ?
ORDER BY
    CASE
        WHEN @order_by = 'asc' THEN name
    END ASC,
    CASE
        WHEN @order_by = 'desc' OR @order_by IS NULL THEN name
    END DESC;

produces this incorrect output (question marks in CASE clauses should instead be same variable)

-- name: ListAuthorsColumnSortDirection :many
SELECT id, name, bio FROM authors
WHERE id > ?
ORDER BY
    CASE
        WHEN ? = 'asc' THEN name
    END ASC,
    CASE
        WHEN ? = 'desc' OR ? IS NULL THEN name
    END DESC

this can still be worked around by using named params in this case.