Patch cancel event to refine bubbling information

[tidoust]

As discussed in #1212, the cancel event bubbles on HTMLInputElement, but it does not bubble on HTMLDialogElement. It does not bubble on CloseWatcher either but that's because CloseWatcher is not part of a bubbling tree.

Events extraction cannot automatically get this nuance, be it only because it only sees HTMLElement as target interface for the event, and not HTMLInputElement and HTMLDialogElement. In practice, it claims that the event bubbles, which is neither wrong nor right.

This patch restricts the cancel entry in the HTML events extract to only target HTMLInputElement, in order to create the right bubbling entry. And it creates another cancel entry which does not bubble for HTMLDialogElement and CloseWatcher.

With this patch (and the new version of Reffy), we should end up with the following entry in the consolidated events.json file, which captures the fact that:

• the event bubbles on HTMLInputElement
• the event does not bubble on HTMLDialogElement
• the concept of bubbling is meaningless on CloseWatcher

{
  "href": "https://html.spec.whatwg.org/multipage/indices.html#event-cancel",
  "src": {
    "format": "summary table",
    "href": "https://html.spec.whatwg.org/multipage/indices.html#event-cancel"
  },
  "type": "cancel",
  "targets": [
    {
      "target": "HTMLInputElement",
      "bubbles": true,
      "bubblingPath": [
        "Node",
        "Document",
        "Window"
      ]
    },
    {
      "target": "CloseWatcher"
    },
    {
      "target": "HTMLDialogElement",
      "bubbles": false
    }
  ],
  "interface": "Event"
}