unique naming option

[s-light]

you can import multiple FreeCAD documents one by one right now -
every import gets its own blender collection - named after the imported file.

the only limitation is: every object needs a unique name.
so if two files contain a object with the same name the later will overwrite the earlier one..
in blender all objects are at the root level of the document - and are only 'linked' to one ore multiple scenes -
the collections are only a visual helper...

it is easy to add an 'unique name' option.
for example just add the self.doc.Name or self.doc_filename in front of the object name.
there is an - currently internal - option obj_name_prefix for a pre string in front of the object names ;-) (see #7)

so its easy to expand this:
get_obj_label(self, obj) (import_fcstd.py#L150)