Feature Request: Harden browser

[fu8765]

I'm unsure whether this is possible or extremely difficult.

The Mull browser from DivestOS (https://github.com/Divested-Mobile/Mull-Fenix) utilizes the Arkenfox user.js (https://github.com/arkenfox/user.js) as default, however, although most sites work, this can be problematic on some others.

It would be a fantastic addition to smartcookie to have a "Very Strict" privacy setting that utilizes these, with a toggle to easily revert to "Strict" or whatever the default is, when something doesn't work.