Description
We're encountering the issue where we cannot walk a VirtualCodebase created from a scancode.io scan (prior to v31.0.0). When the scan is loaded into VirtualCodebase, and we call walk(), only the virtual_root is returned. This is due to the scancode.io Resource names not containing the extensions. The full filename is required for a VirtualCodebase to work since we keep the filenames of the children of each Resource (https://github.com/nexB/commoncode/blob/main/src/commoncode/resource.py#L671). If the filename isn't the complete filename, then the Resource will never find the child Resource when walking.
For example, in the problematic scan, the two resources at the root have the paths example.zip and example.zip-extract, but their names are both example. When loaded into a VirtualCodebase, the virtual_root has two children, but their names are both example, when it should be example.zip and example.zip-extract. Since virtual_root/example does not exist in resources_by_path of the VirtualCodebase, then we cannot continue the walk.