public GFile lookup(String path) {
		return lookup(null, path, null);
	}
Mirrors {@link GFileSystem#lookup(String)} interface.

@param path path and filename of a file to find (either "/" for root or the payload file's
path).
@return {@link GFile} instance or null if requested path is not the same as the payload file.
Ghidra/Features/Base/src/main/java/ghidra/formats/gfilesystem/SingleFileSystemIndexHelper.java