[Feature request] Sleep and retry timers

[NickDegrasse]

I'm just getting up to speed on using gamdl, but so far it seems like a great tool.

I've previously used yt-dlp (soundcloud downloading) and zotify (spotify downloading), and both have sleep/wait timers implemented to get around API limits. The introduction of both:

• Retry timer: a timer that pauses downloading for x seconds when a failure occurs, and retries y times
• Sleep timer: a timer that pauses after each song for x seconds (this is currently what helps get around spotify download limitations, and works well)

would help to ease the issues with some of the experimental codecs