per-channel emote blacklist (hide individual emotes) feature

[BennyyyBB]

Description

I recently saw a users message in the 7TV discord help channel asking for a feature that allows you to hide emotes in a specific twitch chat without having to deactivate the entire 7TV extension. A moderator answered that a feature like this doesn't really exist yet, there is only a way to fully hide an entire message, not only the emotes in it. Therefore I implemented a per-channel emote blacklist that hides specific emotes from chat without hiding the entire message.
Some channels add 7TV emotes to commonly used words, making chat unreadable, which was the point of the 7TV discord user asking for a way to hide them. Users should now be able to hide just the problematic emotes per channel.

• added chat.emote_blacklist_per_channel config as a Map<string, string[]> (channel key → emote names)
• injected hiddenEmotes into the chat tokenizer (tokenize()) on both Twitch and YouTube modules
• added a master toggle chat.emote_blacklist_per_channel.enabled
• added a new settings view to manage blacklisted emotes per channel (remove individual emotes, clear channel, clear all)

-> The settings I changed for YouTube might need more adjustment to be fully integrated. Technically, we could also think about adding this feature for Kick.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged