smp server: combine messages and queue storage to optimise performance, prevent race condition when deleting queue and to avoid "orphan" messages. (#1395)

* smp server: combine queue and message store into one class (WIP)

* keep deleted queue tombstones to prevent race conditions and errors when restoring

* move store log from server to store implementations

* STMQueueStore type class

* fix store closed when messages expired, handle store writing errors

* types

* version

* fix recovery from missing write journal, tests

* version

src/Simplex/Messaging/Server/StoreLog/Types.hs

@@ -0,0 +1,13 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE KindSignatures #-}
+
+module Simplex.Messaging.Server.StoreLog.Types where
+
+import System.IO (Handle, IOMode (..))
+
+-- | opaque container for file handle with a type-safe IOMode
+-- constructors are not exported, openWriteStoreLog and openReadStoreLog should be used instead
+data StoreLog (a :: IOMode) where
+  ReadStoreLog :: FilePath -> Handle -> StoreLog 'ReadMode
+  WriteStoreLog :: FilePath -> Handle -> StoreLog 'WriteMode