Render edited messages

[slondr]

Is your feature request related to a problem? Please describe.
Probably the most immediately-visible difference that makes Nheko look more unrefined/unpolished compared to big-name clients like Element is the ugly handling of edited messages. If someone edits a message, the old message remains and the new one is reprinted with an asterisk in front — this often results in my entire chat window filling up with a single message, or very old messages reappearing when they shouldn't. This is both very ugly and also occasionally prevents me from easily reading the chat history.

Describe the solution you'd like
The content of messages should change when they are edited, instead of remaining + a new message appearing.

[deepbluev7]

Kinda duplicate to #134. The problem is that I disagree with the current proposal for edits (it is not officially part of the matrix spec at this point). Which is why I didn't implement it, since I was hoping for either the proposal to get fixed or it at least get merged into the spec officially. I probably need to implement it at some point now though, since explaining that every time again is no fun...