This commit adds `UrlTree` as a valid input to `routerLink`. It
disallows using this together with any inputs that come from
`UrlCreationOptions`, such as `queryParams` or `fragment`.
We could, in the future, decide on a different approach for these, like merging or
replacing those in `urlTree` input. We cannot, however, go the other way
(decide to prevent those inputs if we've already decided to allow it and
using a merging/replacing strategy). For this reason, an error seems the
most reasonable approach to start and we can re-evaluate if there's a
compelling reason to.
fixes#34468
PR Close#56265
