Make router-handled scrolling work with CSS properties

[allezxandre]

Fixes #1863.

Using scrollIntoView instead scrollTo naturally adds
support for more CSS scrolling properties when scrolling to IDs.

Properties like scroll-margin and scroll-behavior are supported by scrollIntoView.

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Latest commit: f0167c5

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[allezxandre]

This PR is ready, however I can't seem to make the tests pass (on this branch or on master's)

As my proposed change is tiny, I assume this isn't my change that breaks the tests?

[benmccann]

The tests are all passing on the CI. Some are a bit flaky. Maybe they flake out more often on your machine