Now that callers are ensuring that `value` is not `None`, we can further tighten the contract and remove the conditional to account when `None` is passed-in for `value`. Additionally, add a new test vector to account for when an empty string is passed in, which would fail `if no value`.
The `normalize_paths()` utility was doing too much — parsing unstructured configuration path data and dispatching the scrubbed paths to be normalized. Towards moving the parsing of unstructured configuration path data closer towards were configuration occurs, have the utility accept only structured input for normalizing paths.