Allow different playback speeds for voice messages

[PasqualePerilli]

Is your feature request related to a problem? Please describe.
It would be nice for the user to have an option to choose the playback speed of each voice message.

Describe the solution you'd like
Spreed could have a button that lets the user choose the playback speed of each voice message. The user could choose between 1x, 1.5x and 2x.

Describe alternatives you've considered
None.

Additional context
This is a really helpful feature when playing voice messages that many other messaging apps have.