XEP-0308: Last Message Correction - Experimental
"When sending a message, people often introduce typing errors and send a follow-up message to correct them. This specification allows the sending client to flag the second message as correcting the first."
Experimental extension, but interesting and rather trivial to implement in the library level.
Application developer needs to take care of the actual replacing.
Should it trigger a new event, MessageCorrectionEvent?
No event, application developer needs to enable and then check if available