Add edit_response and edit_followup to Interaction class

[jaARke]

These functions are self explanatory. They would allow a user to edit response and followup messages after they have been sent with send_response or send_followup.

edit_response will be straightforward. The API for editing a response only depends upon the Interaction token, which is readily available in our Interaction object.

edit_followup will be more intensive. We will need to develop a way of receiving message data back from the Discord API after sending each followup. send_followup will then need to store and return this message data so that the user can eventually edit the message using the returned object. See this page for relevant documentation.