Enhance `{% ImplementationStatus %}` with additional features

[matthiasrohmer]

Follow up to https://github.com/GoogleChrome/web.dev/issues/9373.

There have been requests, like surfacing multiple, even parallel origin trials in that widget, as well as showing various launch stages (like behind a flag). Additionally after launch it would be good to evolve in something like the BrowserCompat widget.

This is not yet ready to be picked up, as discussion is still ongoing (30 Jan 23)