Access SNS storage using OIDC tokens

create a file source based on ssh that allows login using an OIDC token.

Might require modifications of https://pypi.org/project/fs.sshfs/ to login with the token (similar to what we do in Pulsar https://code.ornl.gov/ndip/pulsar/-/blob/dev/pulsar/managers/util/cli/shell/rshwkey.py#L60).

Also would need to pass the token to the file source (again via an environment variable for now or would it be possible to use user_context)