Throttle feed loading to avoid YouTube rate limits

[Stypox]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

This PR introduces a delay between every BATCH_SIZE=50 channel extractions while loading the feed, to avoid YouTube rate limits and hopefully solve #11661. The delay varies in range DELAY_BETWEEN_BATCHES_MILLIS=(6000..12000) (on average 8s). I also lowered PARALLEL_EXTRACTIONS from 6 to 3, as suggested by AudricV. The value of BATCH_SIZE was chosen because people reported problems starting from ~100 subscriptions, so 50 should be safe.

Before/After Screenshots/Screen Record

In this video BATCH_SIZE=10 and DELAY_BETWEEN_BATCHES_MILLIS=(2000..8000) for demonstration purposes.

screen-20241124-140028.mp4

Fixes the following issue(s)

• Workaround for / fixes 405 Error on reCaptcha page / errors after reloading feed #11661

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.

[TobiGr]

code looks good, did not test the latest change

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Stypox]

I tested it on my phone with BATCH_SIZE=10 and the number of subscriptions did not always increase by exactly 10, indicating that non-YouTube channels do not count towards the throttling.