Make security slider work with NoScript for ESR60

NoScript is now rewritten based on WebExtensions and as such no longer uses prefs. So we need to find another way to control it. Here are the prefs we used:

{{{ "noscript.forbidMedia" : [, true, true, true, false], "noscript.global" : [, false, false, false, true ], "noscript.globalHttpsWhitelist" : [, false, true, true, false], "noscript.forbidFonts" : [, true, false, false, false], }}}