Split ReadOnlyContactDetails into mountContactDetails and fetchContactDetails

[kesselb]

Is your feature request related to a problem? Please describe.

Christoph and I discussed the ReadOnlyContactDetails component.

The issue we ran into in Mail is that using the component multiple times triggers unnecessary extra requests, since each instance fetches the list of address books again.

We’re mitigating this with #4716, and #4794, but we should still look into creating a new version that separates fetching the contact data from rendering the component once we have time.