Add support on playing m4a files without having to download them.

[GamePlayer-8]

Describe the problem

Currently Fluffychat (Android Matrix client) sends the audio messages as m4a. While Cinny supports playing mp3 audio files within the Cinny UI, it doesn't support the m4a audio files.

Describe the solution you'd like

Add support on playing m4a audio files within the browser / client.

Alternatives considered

No response

Additional context

No response

[aceArt-GmbH]

Cinny sends m4a as "msgtype": "m.file", and not "msgtype": "m.audio", (like Element).
But even then it is not playable even if the browser supports it

https://github.com/cinnyapp/cinny/blob/dev/src/app/utils/mimeTypes.ts#L12-L24 does not declare audio/x-m4a as getBlobSafeMimeType audio mime type.
Adding it allows playback in cinny