Change sender_id to contact_id in conversations (#167)

* change sender_id to contact_id in conversations

* Fix failing tests

* Fix seeds

* fix specs

* Fix issues in facebook messenger

app/services/facebook/send_reply_service.rb

@@ -12,6 +12,8 @@ module Facebook
 
     private
 
+    delegate :contact, to: :conversation
+
     def inbox
       @inbox ||= message.inbox
     end
@@ -20,10 +22,6 @@ module Facebook
       @conversation ||= message.conversation
     end
 
-    def sender
-      conversation.sender
-    end
-
     def outgoing_message_from_chatwoot?
       # messages sent directly from chatwoot won't have fb_id.
       message.outgoing? && !message.fb_id
@@ -37,7 +35,7 @@ module Facebook
 
     def fb_message_params
       {
-        recipient: { id: sender.source_id },
+        recipient: { id: contact.source_id },
         message: { text: message.content }
       }
     end