fix and move textmessage to a module

modules/textmessage/textmessage.otmod

@@ -0,0 +1,13 @@
+Module
+  name: textmessage
+  description: Manage game text messages
+  author: OTClient team
+  website: https://github.com/edubart/otclient
+  autoLoad: true
+  dependencies:
+    - game
+
+  onLoad: |
+    require 'textmessage'
+    return true
+