CAM: Corrected Fanuc post processor M3 handling

The thread tapping implementation in the Fanuc post processor change
behaviour of M3, G81 and G82 when the tool ShapeID matches "tap".
but the code not not expect that the parse() method will be
called with two different classes as arguments.

Rewrite the M3 handling to handle ToolController arguments
instead of crashing with an AttributeError.

Issues:

Fixes #14016
Fixes #25723

src/Mod/CAM/Path/Post/scripts/fanuc_post.py

@@ -454,17 +454,19 @@ def parse(pathobj):
                 if command == "G0":
                     continue
 
-            # if it's a tap, we rigid tap, so don't start the spindle yet...
+            # if tool a tap, we thread tap, so stop the spindle for now.
+            # This only trigger when pathobj is a ToolController.
             if command == "M03" or command == "M3":
-                if pathobj.Tool.ShapeID.lower() == "tap":
+                if hasattr(pathobj, "Tool") and pathobj.Tool.ShapeName.lower() == "tap":
                     tapSpeed = int(pathobj.SpindleSpeed)
                     continue
 
-            # convert drill cycles to tap cycles if tool is a tap
+            # Convert drill cycles to tap cycles if tool is a tap.
+            # This only trigger when pathobj is a Operation.
             if command == "G81" or command == "G83":
                 if (
                     hasattr(pathobj, "ToolController")
-                    and pathobj.ToolController.Tool.ShapeID.lower() == "tap"
+                    and pathobj.ToolController.Tool.ShapeName.lower() == "tap"
                 ):
                     command = "G84"
                     out += linenumber() + "G95\n"