Implement EXCEPT and REPLACE in select item

[apstndb]

This PR implements EXCEPT and REPLACE in SelectItem.

Note:

• There is no breaking changes.
• Introduced p.lookaheadStarModifierExcept() to avoid ambiguity between * EXCEPT (columns) and * EXCEPT ALL or * EXCEPT DISTINCT.
• The prefix StarModifier is borrowed from ZetaSQL: https://github.com/google/zetasql/blob/194cd32b5d766d60e3ca442651d792c7fe54ea74/zetasql/parser/gen_parse_tree.py#L3617-L3634

fixes #184