DM-47986: Convert the UWS library to use the Wobbly backend

[rra]

Rather than storing UWS jobs directly in a database, which requires every UWS-based application to manage its own separate database, use the Wobbly service to manage all job storage. This service uses a delegated token to determine the user and service, so considerably less tracking of the user is required.

UWS applications now store the serialized parameter model in the database rather than a list of key/value pairs, and rely on methods on the parameters model to convert to the XML format for the current IVOA UWS protocol.

Add a mock for Wobbly that can be used to test UWS applications without having the Wobbly API available.

Drop the ErrorCode enum, since its values were specific to SODA, and instead take the error code as a string. Drop some related exceptions that are not used directly in Safir and are specific to SODA.

[rra]

The typing here internally is not great — the parameters type is Any throughout much of the internal code for mypy — because I hadn't come up with a good way to do type propagation into the internals. I have subsequently thought of a strategy that should work, but it's a major refactoring, so I'm saving it for a follow-on PR.

[rra]

I should also note that I temporarily removed job expiration. I need to think about the right way to handle that between the application and Wobbly and will re-add it in a later PR.

[fajpunk]

This is great, and I think it reenforces that making Wobbly was the right thing to do. Some minor things, mostly documentation stuff.