Hardening the Firefox Front End with Content Security Policies

Firefox really needs to fix their CSP for extensions before this kind of thing.

Here is the 9 year old bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1267027

And their extension store does not permit workarounds, even though they themselves have confirmed it's a bug.

While this is definitely annoying, most of the time this can be worked around by the extension without workarounds that themself weaken security.

For example I helped uBlock Origin out in 2022 when they ran into this: https://github.com/uBlockOrigin/uBlock-issues/issues/235#iss...