TODO
-[x] respect order of queue
-[x] replacements
-[x] those w/o completion handler
-[x] basic send+log operation persists
-[x] send+ui completion
-[x] share extension
-[x] update state jobs
-[x] App Lifecyle
-[x] settable
-[x] Mark as ready on startup
-[x] Fail appropriate jobs on startup
NICE TO HAVE
-[x] concurrent per senders
-[ ] longer retry (e.g. 24hrs)
-[ ] App Lifecyle
-[x] retry failed jobs on startup?
-[ ] reachability
DONE
-[x] basic passing test
-[x] datamodel
-[x] queue/classes
We were often using `timestampForLegacySorting`, which is convoluted for when
we actually just want received time.
In some sense this is a superficial change, but it's part of auditing that
we've completed moved away from timestampForLegacySorting.
No change in functionality in this commit, I just broke the signature to have a
systematic audit of the callsites. Added TODO's with the plan for each call.
Historically we would backdate the SN change messages, but since adopting
non-blocking SN changes long ago, they're already sorted properly by creation
time, so backdating has been unnecessary for a while.
I also audited that all other error messages are saved directly after creation.
I applied deprecation attributes as appropriate as I audited.
There is no change in functionality in this commit.
Apart from clarifying what the timestamp means (it's the timestamp of the
*sender*), this intentionally breaks all the call sites, so I could have a sane
way to thoroughly audit wherever we're passing in timestamps, to see where
we're depending on them to affect sort order.
For the sake of a cleaner diff of meaningful changes, instead of "fixing"
everything in this commit, I've just added comments and renamed signatures.
