A complete gutting of the internals of ytdl-sub to support functions in our variable syntax, in addition to being able to access a yt-dlp entry's .info.json fields using functions. Functionally, ytdl-sub should still look and behave the same from a user-perspective.
With so many lines of code changed (+8927, -2708), no doubt there will be new issues. Please make a GH issue or reach out on Discord if your config/subscriptions break in any way/shape/form.
Details on how to use function support will come soon in the form of proper documentation in our readthedocs.
Provides options to make ytdl-sub look more 'human-like' to protect from throttling. For range-based values, a random number will be chosen within the range to avoid sleeps looking scripted.
Usage:
```
throttle_protection:
sleep_per_download_s:
min: 2.2
max: 10.8
sleep_per_subscription_s:
min: 9.0
max: 14.1
max_downloads_per_subscription:
min: 10
max: 36
subscription_download_probability: 1.0
```
