Breach Alerts component

[jo]

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[Vinnl]

I can't comment on the Rust code and AS conventions, but I integrated this into Firefox using your patch, and it did what it says on the tin :)

Added some inline suggestions, but none of them are blockers, and for each of them one could also make a valid argument that they should be ignored, so 🤷

[bendk]

The code looks good to me.

My only slight concern is that we should make sure we're tracking any errors that come from this component and fixing them. At some point soon I'd love to set up a dashboard so that credential management can do that. I've been working on the dashboards for a while and I think they're close to being ready for wider use.