[Feature] Make hint-manifest-scoped-urls work with local connector

[antross]

I agree with @molant we should change this to site scope for now and open a separate issue to think about how to best make this work with the local connector in the future.

    scope: HintScope.site

My primary concern for the local connector is that when used with the VS Code extension we can re-run on nearly every keypress. That's a lot of filesystem access due to the fetchContent calls here so we'd probably want to work out some sort of caching like we did for hint-sri in this context.

Originally posted by @antross in #2328