smp server: split postgres support to a separate executable, to not require postgres library in the main binary (#1482)

* smp server: split postgres support to a separate executable, to not require postgres library in the main binary

* comments

* enable server_postgres flag by default, add CPP option to test

* refactor

* change default for server_postgres to False

* diff

src/Simplex/Messaging/Server/QueueStore/Postgres/Config.hs

@@ -0,0 +1,12 @@
+module Simplex.Messaging.Server.QueueStore.Postgres.Config where
+
+import Data.Int (Int64)
+import Simplex.Messaging.Agent.Store.Postgres.Options (DBOpts)
+import Simplex.Messaging.Agent.Store.Shared (MigrationConfirmation)
+
+data PostgresStoreCfg = PostgresStoreCfg
+  { dbOpts :: DBOpts,
+    dbStoreLogPath :: Maybe FilePath,
+    confirmMigrations :: MigrationConfirmation,
+    deletedTTL :: Int64
+  }