After a `Notifier` has been `notify`'d, attempts to `get_future`
should return a `Future` which is pre-completed, however this was
not the case.
This commit simply fixes the behavior, adding a test to demonstrate
the issue.
While we could, in theory, add support to the bindings logic to map
`Box<dyn Trait>`, there isn't a whole lot of use doing so when its
incredibly trivial to do directly.
This adds a trivial wrapper around `Future::register_callback` that
is only built in bindings and which is linked in the
`register_callback` docs for visibility.
This allows users who don't wish to block a full thread to receive
persistence events.
The `Future` added here is really just a trivial list of callbacks,
but from that we can build a (somewhat ineffecient)
std::future::Future implementation and can (at least once a mapping
for Box<dyn Trait> is added) include the future in no-std bindings
as well.
Fixes#1595
It was always somewhat strange to have a bunch of notification
logic in `channelmanager`, and with the next commit adding a bunch
more, its moved here first.
