If the SubsMgr knows the status has because it already announced it to
clients (other clients were subscribed), then this is returned.
Otherwise nothing is returned and client must, as before, grab the full
history to compute the status.
- The crash bug was due to misuse of
robin_hood::unordered_flat_map::erase (it's still kind of bizarre that
it would crash the way it did, but I suppose the next iterator was
invalidated somehow). We instead grab the next returned by .erase() and
now it works ok.
- We redid the ownership model of SubsMgr. Rather than having
Controller own it and pass it all the way down to the Server instances,
we instead have Storage create & own it. This is needed because in the
future Storage may need to invalidate cached sub statuses as blocks are
undone in undoLatestBlock, and/or it may need to atomically add
notifications as blocks are added. So it makes sense for Storage to own
the SubsMgr (as it also owns the Mempool, which has similar ephemeral
qualities).
Not sure why it was crashing in debug mode in ~CtlTask but I think it
was due to a compiler bug using __FUNCTION__ + Debug(printf_format). We
switched it up and it no longer crashes.
