MakeHandler makes a handler that recovers from panics and passes them to the given callback.

RecoveredPanicErr captures panics that happen during execution of a single request or response The assumption is we want to make sure all of graphsync doesn't go down cause a single block load or selector execution fails.

CallBackFn is a function that will get called with information about the panic.

PanicHandler is a function that can be called with the result of revover() within a deferred to recover from panics and pass them to a callback it returns an error if a recovery was needed.