Can't edit markdown source for previously sent message

### Steps to reproduce

1. Write a message as markdown and send it
2. Open it in editing
3. The edit textarea contains formatted text, it should have containing markdown source of the message

### Outcome

You can't edit original message markdown source.

Here a video of the issue:
https://drive.google.com/file/d/1fTRHIk-afQ48gfUVQLYzddYaMecm0kr2/view?usp=drivesdk

### Your phone model

Google Pixel 4a

### Operating system version

Android 13

### Application version and app store

1.6.5 F-Droid

### Homeserver

default

### Will you send logs?

No

### Are you willing to provide a PR?

No