libstdc++: Implement ranges::zip_transform_view from P2321R2

libstdc++: Implement ranges::zip_transform_view from P2321R2

libstdc++-v3/ChangeLog:

	* include/std/ranges (zip_view::_Iterator): Befriend
	zip_transform_view.
	(__detail::__range_iter_cat): Define.
	(zip_transform_view): Define.
	(zip_transform_view::_Iterator): Define.
	(zip_transform_view::_Sentinel): Define.
	(views::__detail::__can_zip_transform_view): Define.
	(views::_ZipTransform): Define.
	(views::zip_transform): Define.
	* testsuite/std/ranges/zip_transform/1.cc: New test.