reply to message stay if edited previous mess

Closes #142 (closed)

DB CHANGES: the db kept track of the id of the message and not the message_id so when the message was being edited the id didn't mach anymore. I've changed it so the column reply_to_message_id points to message_id and not id but that meant changing the type from int to string in the database.

backend/app/models.py

@@ -127,10 +127,14 @@ class Message(Base):
     user_id = Column(Integer, ForeignKey("users.id"))
     session_id = Column(Integer, ForeignKey("sessions.id"))
     created_at = Column(DateTime, default=datetime_aware)
-    reply_to_message_id = Column(Integer, ForeignKey("messages.id"), nullable=True)
+    reply_to_message_id = Column(
+        Integer, ForeignKey("messages.message_id"), nullable=True
+    )
 
     feedbacks = relationship("MessageFeedback", backref="message")
-    replies = relationship("Message", backref="parent_message", remote_side=[id])
+    replies = relationship(
+        "Message", backref="parent_message", remote_side=[message_id]
+    )
 
     def raw(self):
         return [