Store audio playback position

**Is your feature request related to a problem? Please describe.**
When I am listening to an audio message and stop the playback, close the app or opened another conversation, the playback position is not saved, so I have to search for the position I stopped listening when I want to resume.

**Describe the solution you'd like**
I want the playback marker of the audio message to stay at the point where I stopped listening to it. So when I reopen the conversation and tap the play button again, the playback resumes at the position it stopped last time.

**Describe alternatives you've considered**
It would be even better, if the playback resumes like 5 seconds before the point where it was stopped so it is easier to remember the context. Many Apps like instagram are working like that if you are resuming playback of a video.