Project.tms should accept a parameter for authentication

Projects tms layers can be authed in all kinds of ways -- mapTokens, normal tokens, no auth for public projects. But `Project.tms()` assumes with no way of overriding this assumption that you want to use
your jwt that the `rf` client was initialized with. This is an issue in third party applications that have different access needs from what we need when we always have a fresh token.