binary SMP protocol encoding, split Command type to two types (#245)

* binary SMP protocol encoding (server tests fail)

* use 1 byte for bytestring length when encoding/decoding

* Encoding class, binary tags

* update server tests

* negotiate SMP version in client/server handshake

* add version columns to queues and connections

* split parsing SMP client commands and server responses to different functions

* check uniqueness of protocol tags

* split client commands and server responses/messages to separate types

* update types in SMP client

* remove pattern synonyms for SMP errors

* simplify getHandshake

* update SMP protocol encoding in protocol spec

* encode time as a number of seconds (64-bit integer) since epoch

src/Simplex/Messaging/Server/MsgStore.hs

@@ -2,13 +2,13 @@
 
 module Simplex.Messaging.Server.MsgStore where
 
-import Data.Time.Clock
+import Data.Time.Clock.System (SystemTime)
 import Numeric.Natural
-import Simplex.Messaging.Protocol (Encoded, MsgBody, RecipientId)
+import Simplex.Messaging.Protocol (MsgBody, MsgId, RecipientId)
 
 data Message = Message
-  { msgId :: Encoded,
-    ts :: UTCTime,
+  { msgId :: MsgId,
+    ts :: SystemTime,
     msgBody :: MsgBody
   }