Implement Custom Channel Overrides

[scaccoman]

This PR implements new custom channel override logic, which seems to be one of the most requested features:

• Channel overrides: Auto-skip certain categories on certain channels #435
• Conditional auto-skipping #1308
• [Feature Request] "Auto Skip All" toggle to be used temporarily #1251
• [Feature Suggestion] Channel-specific exceptions for segment types #1085
• Don't skip for this video #646

Please see the attached screen recording for a brief demo:
https://user-images.githubusercontent.com/28684618/175990993-94e62021-bdc4-4309-960b-8730cd4bd097.mp4

There are some weird behaviours around disabled segment types, I'm not really sure how it's supposed to work. I would appreciate it if someone more familiar with the project (e.g. @ajayyy) could shed some light.

• I agree to license my contribution under LGPL-3.0 or my contribution is from another project with a license compatible with LGPL-3.0

[ajayyy]

Thanks, but now we have two #1261

I do like how the configuration happens in the popup

[scaccoman]

Damn, I should have checked the open PRs before investing time into this one! 😅

I've taken a look at #1261 and I believe it does a better job overall. IMHO, however, it doesn't mean we should scrap this PR. I believe we could easily adapt the popup.ts code to work on top of @zedseven's implementation.
@ajayyy your feedback would be welcome.

[eirnym]

@scaccoman @ajayyy any news on this feature?