STEP: import missing Edges

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Problem description

this is a long time issue still partially advanced toward the solution...
In importing Prefs, if I don't enable **step compound merge**, edges shapes will be dropped.
I double checked importing the exported STEP file (which is fine) with CAD Assistant 1.6.0
**Test files and discussion** at the FC forum
https://forum.freecad.org/viewtopic.php?t=77994
The issue is present with the importing settings added at the [forum post](https://forum.freecad.org/viewtopic.php?p=791488#p791488)

### Full version info

```shell
OS: Windows 10 build 18363
Word size of FreeCAD: 64-bit
Version: 1.0.0RC2.38806 (Git)
Build type: Release
Branch: (HEAD detached at 1.0rc2)
Hash: 3d63fc6c2f665a8d5e6468845a419bcac80756c7
Python 3.11.9, Qt 5.15.13, Coin 4.0.3, Vtk 9.2.6, OCC 7.7.2
Locale: English/United Kingdom (en_GB)
Stylesheet/Theme/QtStyle: unset/FreeCAD Classic/Qt default
```

### Subproject(s) affected?

None

### Anything else?


### Code of Conduct

- [X] I agree to follow this project's Code of Conduct