Fast-fail on old Chrome/Firefox versions

[SebastienGllmt]

trafficstars

We can get the browser version from the user agent string (see userAgentInfo.js. Currently Yoroi only works on the versions mentioned in https://github.com/Emurgo/yoroi-frontend/pull/862

We should probably have the app refuse to load on old browser versions instead of failing the first time web assembly is used.

[jarstorm]

Hello, and thank you for your contribution. We're currently reviewing long-standing issues to keep the tracker manageable. As this issue hasn't seen activity in some time, we're closing it. If the problem persists or you'd like to follow up, feel free to comment and we'll reopen it.