Move HTTPS Everywhere into omni.ja
At best it is brittle having our HTTPS Everywhere signature exception along with the desired v3 add-on blocklist mechanism. At worst HTTPS Everywhere is broken or disabled.
So, Mozilla engineers recommended putting HTTPS Everywhere into the omni.ja making it a system extension which does not need to be signed.
That's essentially the same path we took for Torbutton and Tor Launcher.