Record what Azure DevOps holds for a batch of the integration's issues

Records each observation on mabl's copy of the issue only, ignoring one older than the revision already stored. An issue may appear once per batch. An existence_changed outcome means the issue flipped between present and deleted, which revisions cannot order, so the caller should read that work item again and send a fresh observation. Never retry a request automatically: a lost response is settled by the next read. After a call that timed out, do not release the lock; let it lapse, so no other holder writes while the request may still be running. Requires the integration's sync lock. Restricted to API keys with global write permission on integrations.