…sition (#33191)

And that doesn't disable with `update="none"`.

The principle here is that we want the content of a Portal to animate if
other things are animating with it but if other things aren't animating
then we don't.

This is a partial revert of #33094. It's true that we don't need the
server and client ViewTransition names to line up. However the server
does need to be able to generate deterministic names for itself. The
cheapest way to do that is using the useId algorithm. When it's used by
the server, the client needs to also materialize an ID even if it
doesn't use it.