Allow configuring which browsers appear on Interop dashboard

[AtkinsSJ]

The Interop dashboard is great for seeing how well the major browsers are doing in implementing features compatibly. But as a developer on a newer browser engine, it's also useful to see which features are upcoming and will start to be expected by websites (out of the many different features being developed at any one time.) Currently there's no easy way to check "how well is Flow/Ladybird/Servo doing in these areas?" It's possible to manually construct links, but it would be appreciated if the dashboard provided a way to configure the listed browsers, similar to the other pages.

For example, a link a Ladybird contributor shared for viewing the Interop 2025 categories looks like this, which is quite unwieldy and required manually specifying all the labels:

https://wpt.fyi/results/?label=master&label=experimental&product=ladybird&product=chrome&product=firefox&product=safari&product=flow&product=servo&view=interop&q=label%3Ainterop-2025-backdrop-filter%20%7C%20label%3Ainterop-2025-core-web-vitals%20%7C%20label%3Ainterop-2025-anchor-positioning%20%7C%20label%3Ainterop-2025-details%20%7C%20label%3Ainterop-2021-flexbox%20%7C%20label%3Ainterop-2023-flexbox%20%7C%20label%3Ainterop-2021-grid%20%7C%20label%3Ainterop-2023-grid%20%7C%20label%3Ainterop-2022-subgrid%20%7C%20label%3Ainterop-2025-modules%20%7C%20label%3Ainterop-2025-navigation%20%7C%20label%3Ainterop-2023-events%20%7C%20label%3Ainterop-2025-remove-mutation-events%20%7C%20label%3Ainterop-2025-scope%20%7C%20label%3Ainterop-2025-scrollend%20%7C%20label%3Ainterop-2025-storageaccess%20%7C%20label%3Ainterop-2025-textdecoration%20%7C%20label%3Ainterop-2025-urlpattern%20%7C%20label%3Ainterop-2025-view-transitions%20%7C%20label%3Ainterop-2025-webassembly%20%7C%20label%3Ainterop-2025-webcompat%20%7C%20label%3Ainterop-2025-webrtc%20%7C%20label%3Ainterop-2025-writingmodes

[gsnedders]

This is really a question for the Interop team.

In general, we probably don't want to allow this — for the same reasons as why we've talked about a separate mobile dashboard, we don't really want people to just be able to select the mobile browsers.

I think we could potentially open it up to allow other browsers to be shown, such as Ladybird, if the vendors want — even if these aren't shown in the "default" view.

We could also provide a link such as the above for the "Total" row on the Interop dashboard — but that doesn't actually give you the score that product would receive, given each focus area is scored individually and the focus area scores are then averaged.