Fix source comment typos

Found via `codespell -q 3 -L aci,ake,aline,alle,alledges,alocation,als,ang,anid,apoints,ba,beginn,behaviour,bloaded,bottome,byteorder,calculater,cancelled,cancelling,cas,cascade,centimetre,childs,colour,colours,commen,connexion,currenty,dof,doubleclick,dum,eiter,elemente,ende,feld,finde,findf,freez,hist,iff,indicies,initialisation,initialise,initialised,initialises,initialisiert,ist,kilometre,lod,mantatory,methode,metres,millimetre,modell,nd,noe,normale,normaly,nto,numer,oder,ontop,orgin,orginx,orginy,ot,pard,parms,pres,programm,que,recurrance,rougly,seperator,serie,sinc,strack,substraction,te,thist,thru,tread,uint,unter,vertexes,wallthickness,whitespaces -S ./.git,*.po,*.ts,./ChangeLog.txt,./src/3rdParty,./src/Mod/Assembly/App/opendcm,./src/CXX,./src/zipios++,./src/Base/swig*,./src/Mod/Robot/App/kdl_cp,./src/Mod/Import/App/SCL,./src/WindowsInstaller,./src/Doc/FreeCAD.uml,./build/doc/SourceDocu`

src/Mod/Path/PathScripts/PathFeatureExtensionsGui.py

@@ -75,7 +75,7 @@ class _Extension(object):
         crd = coin.SoCoordinate3()
         fce = coin.SoFaceSet()
         hnt = coin.SoShapeHints()
-        numVert = list()  # track number of verticies in each polygon face
+        numVert = list()  # track number of vertices in each polygon face
 
         try:
             wire = ext.getWire()
@@ -285,7 +285,7 @@ class TaskPanelExtensionPage(PathOpGui.TaskPanelPage):
         Subroutine called inside `setFields()` to initialize Extensions efficiently."""
         if self.enabled:
             self.extensions = FeatureExtensions.getExtensions(obj)
-        elif len(obj.ExtensionFeature) > 0:  # latter test loads pre-existing extensions (editting of existing operation)
+        elif len(obj.ExtensionFeature) > 0:  # latter test loads pre-existing extensions (editing of existing operation)
             noEdges = True
             for (__, __, subFeat) in FeatureExtensions.readObjExtensionFeature(obj):
                 if subFeat.startswith("Edge") or subFeat.startswith("Wire"):