Firefox < 77 cannot navigate in Zimit files due to lack of support for replaceAll()

[Jaifroid]

Other browsers with lack of support for replaceAll (see https://caniuse.com/?search=replaceAll) don't support ServiceWorker mode anyway. We could trigger an automatic fallback to jQuery mode if a user opens a Zimit archive and replaceAll isn't supported.

We can't easily polyfill this because it appears in wombat setup, which is loaded in article context. These are very old browsers now, anyway. The best we could really do is fallback to reading the file in Restricted mode (aka jQuery mode).

For more details see: #1296 (comment)