Add support for blocking moz-extension: pages

[KrasnayaPloshchad]

In Bugzilla@Mozilla there are some people required blocking moz-extension:// pages in history, but the developer refused to do. See following bug report and its duplacates: https://bugzilla.mozilla.org/show_bug.cgi?id=1314123

However that’s not means there is no way to block such pages in browser history, it’s possible to be done by extension.

[Grossdm]

Wow, I would love this feature!