Support Text Fragment scrolling

[RangerMauve]

There's a WICG spec for text fragments which lets you specify a range of text in the # portion of a URL in order to have the browser automatically scroll to it. https://github.com/WICG/scroll-to-text-fragment

It'd be useful if we could integrate this functionality:

• Support the scroll and selection stuff when navigating to such a URL
• Right-click context menu with lets you generate and copy a URL that embeds the selected text as a text fragment.

Given we use Electron and Chromium, it might already be possible to do the scrolling thing. Else we'd need to do it manually.

Help to look into how this could be done or a PR which adds the functionality would be very much appreciated.

[RangerMauve]

I just tested this out and it seems to already work!

For example: https://web.dev/text-fragments/#:~:text=deep%20link