After logging in, nodeinfo is required for all API requests, but Resquestor is allowed to continue without it

[fixmycode]

In the presence of an auth token, the requestor selects the strategy to authenticate using nodeinfo's version, but there's a situation where the request for nodeinfo could have failed and the information is not available to make a decision. The requestor is allowed to instantiate because raise_exceptions is False.

If nodeinfo is necessary to make that decision, Requestor's nodeinfo should be refactored as a getter, which can return the saved value or request the nodeinfo again.