MakeLocalStorageURI converts a local path (should always be relative) to a valid nodelocal URI.

ReplaceNodeLocalForTesting replaces the implementation of of nodelocal with one reads and writes directly from the given directory.

TestingMakeNodelocalStorage constructs a nodelocal storage for use in tests.

LocalRequiresExternalIOAccounting is the return values for (*localFileStorage).RequiresExternalIOAccounting.