Reference select dialog needs to be reworked

Issue imported from https://tracker.freecad.org/view.php?id=3186

* **Reporter:** ickby
* **Date submitted:** 9/15/2017
* **FreeCAD version:** 0.17
* **Category:** Bug
* **Status:** assigned
* **Tags:**

# Original report text

The reference select dialog is not yet ported to the new linked scope restrictions and does hence not really work right now.
When working on it the code structure of that functionality can be revised and made more elegant. It's a mess.

https://forum.freecadweb.org/viewtopic.php?f=10&t=20749&start=30#p187270

# Other bug information

* **Priority:** high
* **Severity:** major
* **Category:** Bug
* **Updated:** 2/6/2021