Feature Request: Hide Social Media Widgets with cosmetic filters

[yokoffing]

We could do one of two options:

1. Under "Ad Block Lists", add a fourth option: Ads + Tracking + Annoyances + Social Media Widgets. As far as community lists go, we could use Fanboy's Social List, AdGuard Social Media, and Dandelion Sprout's Lightweight Anti-'Social share' List.

2. The alternative could be to bolster the already implemented Ads + Tracking + Annoyances to include social media widgets (my preference). Remi said in #558 (comment) that we're already using Easylist Cookie in the Annoyance preference. However, we could switch out both Fanboy's Social and EasyList Cookie for one unified list, Fanboy's Annoyance (since both of these list are inherent in Fanboy's Annoyance), thus eliminating more annoying elements on the Web. We would include AdGuard Annoyances, AdGuard Social Media, and Dandelion Sprout's Lightweight Anti-'Social share' List.

@remusao @christophertino