Ytdl-sub

[FEATURE] Subscription nesting (747)

Closes Feature Request: https://github.com/jmbannon/ytdl-sub/issues/743

Subscriptions support using presets as keys, and using keys to set override variables as values.
For example:


tv_show:
only_recent:
[News]:
"Breaking News": "https://www.youtube.com/SomeBreakingNews"

[Tech]:
"Two Minute Papers": "https://www.youtube.com/TwoMinutePapers"

Will create two subscriptions named "Breaking News" and "Two Minute Papers", equivalent to:


"Breaking News":
preset:
- "tv_show"
- "only_recent"

overrides:
subscription_indent_1: "News"
subscription_name: "Breaking News"
subscription_value: "https://www.youtube.com/SomeBreakingNews"

"Two Minute Papers":
preset:
- "tv_show"

overrides:
subscription_indent_1: "Tech"
subscription_name: "Two Minute Papers" subscription_value: "https://www.youtube.com/TwoMinutePapers"


You can provide as many parent presets in the form of keys, and subscription indents as ``[keys]``.
This can drastically simplify subscription definitions by setting things you want configurable like so in your
parent preset:


presets:
tv_show_name:
overrides:
tv_show_name: "{subscription_name}"
url: "{subscription_value}"
genre: "{subscription_indent_1}"


NOTE!!!
Changing your subscription name from 'legacy' subscriptions will need their download archive file migrated to a new name. A future update will assist in this migration process. Either wait until then or, if you consider yourself a ytdl-sub expert, keep a backup of your subscription file before migrating.

[FEATURE] Ability to add subscription value via config (744)

`Subscription Value` is the mechanism used to achieve one-liner subscriptions. It works by having the subscription `"Subscription Name": "value"`, and assigning `"value"` to an override variable via setting the subscription value to that override variable's name.

This feature allows you to set subscription value within the config. In the near future, ytdl-sub will strive to make subscription files simpler by hiding most of the "under-the-hood" logic within the config file.

[BACKEND] Always filter out live, post_live, and upcoming videos on download (742)

Closes Issue: https://github.com/jmbannon/ytdl-sub/issues/729

Add a new field to the match_filter plugin: `download_match_filters`. This set of filters will be applied at the download stage (as opposed to `filters` which get applied at the metadata stage). By default, always set `"!is_live & !is_upcoming & !post_live"` as a download filter. This prevents ytdl-sub from hanging when trying to grab live and upcoming videos.

Docs on match-filters: https://ytdl-sub.readthedocs.io/en/latest/config.html#match-filters

[BACKEND] Update yt-dlp to 2023.9.24 (741)

[REVERT] Remove default match-filter that filters live videos (739)

Adding a default match-filter broke other people's match-filters. This is because each match-filter acts as an OR. I.e.

match_filters:
filters:
- "!is_live & !is_upcoming & !post_live" the one I added
- "original_url!*=/shorts/ & !is_live"

Would not filter shorts, because under the hood, yt-dlp evaluates it as `(!is_live & !is_upcoming & !post_live) | (original_url!*=/shorts/ & !is_live)`

Need to rethink how to filter live videos by default :thinking:

[BACKEND] Filter out upcoming videos and post-live streams by default in TV show presets (738)

Follow-up to filtering out live videos. YouTube channels with an upcoming video that hasn't premiered yet would also hang ytdl-sub. Perform a match-filter to skip those as well.

More info on match-filters here: https://ytdl-sub.readthedocs.io/en/latest/config.html#match-filters