APNS/HTTP2 push client for notifications server (#350)

* APN push client (WIP)

* APNS push client works

* TODO comments

* comment

* send notification and process the response

* config

* e2e encryption for notification parameter

* read apns key filename and ID from env

* connect APNS client to server, fix notification JSON encoding to use dash case

* do not connect to APNS on start to pass CI tests

* fix CI test

* remove redundant import

tests/SMPClient.hs

@@ -45,7 +45,7 @@ testStoreLogFile = "tests/tmp/smp-server-store.log"
 
 testSMPClient :: (Transport c, MonadUnliftIO m) => (THandle c -> m a) -> m a
 testSMPClient client =
-  runTransportClient testHost testPort testKeyHash (Just defaultKeepAliveOpts) $ \h ->
+  runTransportClient testHost testPort (Just testKeyHash) (Just defaultKeepAliveOpts) $ \h ->
     liftIO (runExceptT $ smpClientHandshake h testKeyHash) >>= \case
       Right th -> client th
       Left e -> error $ show e