Display warning if on incognito

[benthecarman]

No description provided.

[futurepaul]

https://security.stackexchange.com/questions/9037/can-web-sites-detect-whether-you-are-using-private-browsing-mode

looks like there a ton of techniques that have been used (it's especially used by news websites to detect if someone is trying to get around their free article limit it seems), but many have been patched

I get a false negative on this link for instance: https://output.jsbin.com/tazuwif

but visiting an article on bostonglobe.com gets this response:

the returned fact in Meter.js is: {"fmSetDate":"20230505","freeViewCount":"0","contentSeen":[],"requestedContentExemptFromMeter":false,"incognito":true,"requestedLOID":"D52MQMKVFJB37EZEIGEH4SADRY","requestedUUID":"D52MQMKVFJB37EZEIGEH4SADRY","exemptFromMeter":false,"arcMode":true,"newsletterVisit":false,"result":true,"incognitoImpression":true,"incognitoPaywall":true,"paywallType":"incognito paywall","matchPath":["Fire Incognito Impression","Show incognito paywall"]}