Finalized implementing channel specific settings

[gosha305]

• I agree to license my contribution under GPL-3.0 and agree to allow distribution on app stores as outlined in LICENSE-APPSTORE

To test this pull request, follow the instructions in the wiki.

---

Combines implementation of channel specific category selections from #1372 (for the popup UI) and #1261. Thank you to both @zedseven and @scaccoman, as I likely wouldn't have even attempted this were it not for their previous work.

Additional minor changes also include:

• Slightly modifying the popup UI in order to account for other languages having longer skip option and category names
• Changing the inherit option's name to global in order to clearly convey that it uses the option selected in the global config
• Adding a clarification of what the currently selected global option is, in parentheses

• Adding a delete channel settings button in the popup (otherwise, the settings are only deleted if their category selections are empty)

Finally, removes the whitelist system entirely. Instead, existing whitelists are converted to have all non-disabled categories at Show overlay in the channel settings.

Also see ajayyy/ExtensionTranslations#81