public String getPathname() {
			if (parent == null) {
				return SEPARATOR;
			}
			return getPath(parent.getPathname(), name);
		}
Set this items parent, name and storage name and add the modified item
to the specified parent's item map.  The FileID will be read from the
existing property file
@param parent
@param name
@param fileId unique file ID from property file content
@param storageName
Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/IndexedLocalFileSystem.java