Remove hacks like changeCssFontPath

[lidel]

Not urgent, just filling issue so we dont forget to clean this up

My understanding is that the hack in changeCssFontPath was introduced as a way of demoing how websites can load without having to set up proper origin isolation just for the iframe-based demo.

As part of productizing, we should remove hacks like this: only subdomain-based isolation is supported for web hosting of arbitrary sites and dapps.

The fact that some things do not work on path gateways is "a feature, not a bug",
and if anything, we should warn users who use path gateway for website hosting, as noted in #30.

[lidel]

@SgtPooki isdo you remember if isReferrerPreviouslyIntercepted similar type of fixup?

[SgtPooki]

I think it is. I tested removing it locally and seemed unnecessary

[SgtPooki]

I believe this is done with #96