Show ItemPart relationships on the front end

[pastokes]

It would be very useful to indicate related ItemParts in the search results and also in the 'manuscripts view' page. What I'm imagining in the search results page is something like a 'plus' icon to indicate that there are more parts to this manuscript, and clicking on it would list those parts would then list the relevant ItemParts. In theory these additional IPs could be those connected through the CurrentItem or through the HistoricalItem, though the emphasis on the search results is through HistoricalItems so I think this alone would be enough.
Similarly (and, arguably, more importantly), in the manuscripts record view page, it seems relevant to list the other ItemParts for the corresponding HistoricalItem and perhaps CurrentItem somewhere there.