Add chat badges to HTML downloads

[yann-a]

Hi, this is my attempt at adding chat badges to HTML downloads.

[yann-a]

Some parts I'm a bit unsure of:

• When embedData is true, it should probably create a dictionnary of (_id, version) to badge instead of iterating over chatRoot.embeddedData.twitchBadges for every chat badge, but it's unclear for me why chatRoot.embeddedData.twitchBadges isn't already a dictionnary
• I think creating BadgeResponse.cs was necessary? It's kind of a duplicate of Api/TwitchBadgeResponse.cs, but it's not in the scope of the api. Also, I'm not sure of my class names there.

[ScrubN]

but it's unclear for me why chatRoot.embeddedData.twitchBadges isn't already a dictionary

Because backwards compatibility

[yann-a]

I updated the PR to use EmbedChatBadge and factor the GetChatBadgesData code. I rebased on your upstream changes because they were conflicting.

[ScrubN]

Looks awesome, and chat JSONs are unaffected aside from the empty URL list. Thanks for the PR!

Also I noticed that there is a scaling issue with first party emotes. I'll fix that once this is merged.