[Path] bug fixes for dxf_post and simulator

[sliptonic]

• Your pull request is confined strictly to a single module. That is, all the files changed by your pull request are either in App, Base, Gui or one of the Mod subfolders. If you need to make changes in several locations, make several pull requests and wait for the first one to be merged before submitting the next ones
• In case your pull request does more than just fixing small bugs, make sure you discussed your ideas with other developers on the FreeCAD forum
• Your branch is rebased on latest master git pull --rebase upstream master
• All FreeCAD unit tests are confirmed to pass by running ./bin/FreeCAD --run-test 0
• All commit messages are well-written ex: Fixes typo in Draft Move command text
• Your pull request is well written and has a good description, and its title starts with the module name, ex: Draft: Fixed typos
• Commit messages include issue #<id> or fixes #<id> where <id> is the FreeCAD bug tracker issue number in case a particular commit solves or is related to an existing issue on the tracker. Ex: Draft: fix typos - fixes #0004805

And please remember to update the Wiki with the features added or changed once this PR is merged.
Note: If you don't have wiki access, then please mention your contribution on the 0.20 Changelog Forum Thread.

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[freecadci]

for feature branch PR_5352. Pipeline 443700928 was triggered at 0d63b87. All CI branches and pipelines.