Since Py3.11 the methods names __setstate__ and __getstate__ conflict with the method names added to the object class.
Thus rename them to 'loads' and 'dumps'
to make the BOPTools available in python3 the way to import these tools had to be changed:
old: ```from Part import BOPTools``` -> new: ```import BOPTools```
this is also changed for python2
* display originals in tree under the features (like Part Fuse does)
* unhide originals upon delete
* display message box when computing the feature fails on creation
Attributions:
Mark (quick61) - icons
Yorik - help with internationalization
Everyone who appeared in forum thread "A new Part tool is being born...
JoinFeatures!" - for endorsement!
http://forum.freecadweb.org/viewtopic.php?f=22&t=11112
