[FEATURE] Add `--dl-override` to pass dl arg overrides to all subscriptions (882)
With both `--match` and `--dl-override`, it is now possible to more easily experiment with subscriptions without needing to create a separate file.
For example, suppose you are changing some values in your subscription "Rick A" and want to test them out. You can now run:
ytdl-sub sub --dry-run --match Rick --dl-override '--ytdl-options.max_downloads 3'
This will
1. Dry-run
2. Only run for the subscription "Rick A"
3. Apply setting max_downloads to 3