[Draft] Improved Snapper Toolbar Behaviour

Changed snap toolbar behaviour:
- create a list of available snaps (Gui.Snapper.snaps)
- make it consistent with Snap Gui Commands (in gui_snaps module)
- create a list of active snaps (Gui.Snapper.active_snaps)
- refactor the isEnabled() method to allow it to check if the given snap is in Gui.Snapper.active_snaps and not if the snap toolbar button isChecked()
- updated and reordered the new list of gui snap commands in draftutils.init_tools and used it as a base to refactor the creation of draft toolbar
- updated all the draft snap gui tools to make them control the toolbar buttons directly
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src/Mod/Draft/DraftGui.py

@@ -1893,8 +1893,7 @@ def getXPM(self,iconname,size=16):
         return str(a)
 
     def togglesnap(self):
-        if hasattr(FreeCADGui,"Snapper"):
-            FreeCADGui.Snapper.toggle()
+        FreeCADGui.doCommand('FreeCADGui.runCommand("Draft_Snap_Lock")')
 
     def togglenearsnap(self):
         if hasattr(FreeCADGui,"Snapper"):