Improve audio codec handling in remux.js

[avandeweghe]

Refactor audio codec handling to conditionally add aac_adtstoasc filter based on codec detection.

[jackduckworth]

Without this code change, every combination of flags (Force Backend Proxy, Auto Transcode, Force Remux) results in a non-playing stream, and a server error:

[mp4 @ 0x564d1e6ae140] Malformed AAC bitstream detected: use the audio bitstream filter 'aac_adtstoasc' to fix it ('-bsf:a aac_adtstoasc' option with ffmpeg)

This change is the only way I have found to get M3U streams to work for me.

(I dont get any sound with firefox, for some reason, but I can hold my nose and use chrome.)

[freakshock88]

This also fixed a lot of video issues for me, exactly how @jackduckworth reports.
For anyone using docker-compose, you can temporarily use the fixes by OP by using this setup:

  nodecast-tv:
    build: https://github.com/avandeweghe/nodecast-tv.git#patch-2
    #image: ghcr.io/technomancer702/nodecast-tv:latest

[technomancer702]

I'll review and merge this as soon as possible. I'm out of the country on business currently with little time for dev.