Declarative Web Push: Flatten the JSON structure, removing the `options` sub-object. This makes more sense when reconciling the JSON structure with the JS API additions.
<rdar://problem/116003373>
Pull request: https://github.com/WebKit/WebKit/pull/18177
Committed 268408@main (d3f529899e76): <https://commits.webkit.org/268408@main> Reviewed commits have been landed. Closing PR #18177 and removing active labels.