[CALCITE-7557] Linq4j.ListEnumerable.take(int) / skip(int) diverge from EnumerableDefaults on negative counts

ListEnumerable specializes take(int) and skip(int) for lists, but unlike
the adjacent BigDecimal overloads, which clamp via count.max(BigDecimal.ZERO),
the int versions pass the count straight to List.subList. A negative count
therefore threw IllegalArgumentException from take and
IndexOutOfBoundsException from skip, while the generic EnumerableDefaults
path returns an empty enumerable and the original sequence respectively.

Clamp the count to zero in both methods so that the optimized list path
agrees with the generic path. Math.max is used rather than negating the
count so that Integer.MIN_VALUE does not overflow.