Add the Mechanical APDL 'ANF' file type to import_cad

### 📝 Description of the feature

In MAPDL the ANF file format, [ANF](https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v232/en/ans_ope/Hlp_G_OPE6_NeutralFile.html?q=anf), is the cleanest geometry that it can export. Would it be possible to add importing ANF files? We have many customers with MAPDL scripts that create geometry, and it would be nice to be able to step over to PyPrimeMesh for meshing, then back to MAPDL (via PyMAPDL).

### 💡 Steps for implementing the feature

No idea. Perhaps it is better for PyGeometry to add an importer for ANF files, then we can export SDOC file and go to PyPrimeMesh from there?

### 🔗 Useful links and references

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v232/en/ans_ope/Hlp_G_OPE6_NeutralFile.html?q=anf

Start by locating the existing import_cad entry point and reviewing how PyPrimeMesh currently accepts geometry. Compare the ANF reference with the existing PyGeometry and SDOC path, then determine where the importer belongs. Done means the import route is agreed and ANF geometry can move from MAPDL into PyPrimeMesh for meshing and back via PyMAPDL.

Written by the indexing model from the issue text.