Peaks display request for instrument view

Message from Pascal Manuel via mantid help:

When you select an area in "Peak", it does a crude focussing which is very useful. 
It would be good to include any peaks from PeakWorkspace(s) the that is/are plotted in the resulting detector plot view.

Hi Pascal,

I’ve created this issue for your feature request. @mantid_roman is assigned to it for the 3.6 release, he may have more questions about your feature.