RBAC functions should raise a FeastAuthenticationError

[dmartinol]

Expected Behavior

When the token extractor cannot find the requested authentication token, it should throw a FeastAuthenticationError instead of the starlette.authentication.AuthenticationError. In this way it would fall into the case of the managed FeastErrors mapped by the Feast servers towards the prox clients.

Current Behavior

starlette.authentication.AuthenticationError is raised.

@lokeshrangineni