Add "Select in PCB" action to eeschema group selection (lp:#1831444)

Original report created by eelik (eelik)

Selecting one symbol in eeschema selects the corresponding footprint in the
layout editor, but why not apply it to group selection, too? Just add
"Select in PCB" menu item to the context menu (if more than one symbols are
selected), and when it's clicked, select the footprints of all the selected
symbols.

This idea came up when I had an IC and the related components in a
schematic and thought, frustrated, that I should create a hierarchical
sheet only because I want to select those footprints together.

Original tags: eeschema pcbnew