ActivityGraph Tooltip should show the sample's page

I noticed that the tooltip in the activity graph (that's the tooltip with SampleTooltipContents) doesn't show the sample's page url.
As a preliminary task, it would be good to extract and merge the code for pages in the existing tooltips:
https://github.com/firefox-devtools/profiler/blob/8da8e85846efc90971908ad6fd765f08234018a8/src/components/tooltip/Marker.js#L100-L146
and
https://github.com/firefox-devtools/profiler/blob/8da8e85846efc90971908ad6fd765f08234018a8/src/components/tooltip/CallNode.js#L243-L284
They both do interesting but different things.

Afterwards we can use that in https://github.com/firefox-devtools/profiler/blob/8da8e85846efc90971908ad6fd765f08234018a8/src/components/shared/SampleTooltipContents.js#L62, probably right before the Stack.

We could also move SampleTooltipContents from `shared` to `tooltip` in the process.

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-454)