In the event that a secret name is structured, such as the URL-like
notation used by Keeper Secrets Manager, canonicalizing/encoding the
entire name could result in the name itself becoming invalid. Only the
portions that come from tokens should be canonicalized.
The "GUAC_USERNAME" token provided by the webapp is based off the
username provided by the user when they authenticated. The username
token provided by the vault extensions uses the username stored with
the user's corresponding object, which may not be the same.
