Misc. comment typos

+ Found via `codespell -q 3 --skip="*.po,*.ts,./.git,./src/3rdParty,./src/CXX,./src/zipios++,./src/Mod/Assembly/App/opendcm" -I ~/Projects/fc-word-whitelist.txt`

+ crowdin translation refinements:  
- https://crowdin.com/translate/freecad/6766/en-en#6499546
- https://crowdin.com/translate/freecad/6766/en-en#6504496

src/Mod/Material/MaterialEditor.py

@@ -70,7 +70,7 @@ class MaterialEditor:
         QtCore.QObject.connect(self.widget.ButtonOpen, QtCore.SIGNAL("clicked()"), self.openfile)
         QtCore.QObject.connect(self.widget.ButtonSave, QtCore.SIGNAL("clicked()"), self.savefile)
 
-        # add material properies (the keys) to the editor
+        # add material properties (the keys) to the editor
         for group in getMaterialAttributeStructure(True):  # get the mat file structure from material module, use Spaces for better ui
             # print(group)
             self.addPropertiesToGroup(group)