Ntfy: support auth tokens

[griefie]

Added optional auth_token support for ntfy notifications:

• the ntfy messenger now accepts an auth token in the config, encodes it as the ntfy auth query parameter, and redacts it from logs so private ntfy servers can be used securely.
• Config templates (evcc.dist.yaml, assets/js/components/Config/defaultYaml/messaging.yaml) were extended to include the new authToken field

once this is accepted i could make a PR for the docs