gui: show all components affected by the aspect

[honzakutil]

There is nice feature in kivar-cli: kivar-cli list --detailed board.kicad_pcb. Maybe it would be worth to add something like this also into the GUI. For example:

• add button "details" or "show components" next to dropdown for each listed aspect
• to the bottom part of the gui, add second tab with name "aspect details"
• when "details" / "show components" button is clicked, all associated components are listed in the bottom part of the GUI
• listed components are clickable - same as they are, when listed for chages when selecting variation choices
• instead of adding button "details" for each aspect, it could be activated by opening the dropdown. Or, aspect name itself could be the button