Adds the mechanism to partially resolve an entire script (aka every underlying variable in ytdl-sub). This will be used in the upcoming `inspect` sub-command where it will dump a subscription's raw contents at multiple levels of resolution.
Potentially useful to optimize script execution as well.
Completely rewrite how subscription validation is performed. Optimizes it quite a bit while also adding backend support for the upcoming `dissect` sub-command, where you can resolve any subscription into its 'raw' form for easier debugging when making scripting changes.
With the right functions, it was possible for subscription validation to raise a false-positive error. This should hopefully resolve that issue and give validation a small performance increase
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.
