Limit component match result iteration to group name list size

[shannonbooth]

User-provided regexp parts may contain nested capturing groups, causing execResult to contain more captures than there are URLPattern groups.

• At least two implementers are interested (and none opposed):
  • Multiple implementations already implement
• Tests are written and can be reviewed and commented upon at:
  • https://github.com/web-platform-tests/wpt/blob/cfce2c045229bb078cb363298f52b3ea0a31acd7/urlpattern/resources/urlpatterntestdata.json#L3146 (specifically see the last commit from gecko)
• Implementation bugs are filed:
  • Chromium: Seems already implemented
  • Gecko: Already patched
  • WebKit: Looks like they have patched this
  • Deno: Seems already implemented
  • kenchris/urlpattern-polyfill: Already implemented
• MDN issue is filed: N/A
• The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

[annevk]

Thanks @shannonbooth!