Remove ServiceStatus.RECOVERING

[wintersteiger]

During discussion of #3679 @jumaffre pointed out that we could remove ServiceStatus.RECOVERING (here) because it is essentially equivalent to ServiceStatus.OPENING && previous_service_identity_version != std::nullopt.

I think this is correct, but the separate state is still valuable as it conveys a clear intention, e.g. in the transition_service_to_open proposals, which would be much harder to read without it. Keeping it would also make it easier to change the service identity recording scheme later (e.g. in case we re-decide to keep a full table of previous identities).

[achamayou]

@wintersteiger I'm confused, this looks like a ticket for "remove A", which exclusively contains reasons why we should keep A? :)

What I am missing? What's the motivation for removing A?

[wintersteiger]

Turns out I misunderstood @jumaffre 's comment, opening a replacement issue.