script: Fire scroll event whenever JS scrolled (#38321)

Implement JS scroll event firing compliant to
https://drafts.csswg.org/cssom-view/#scrolling-events. Basically
whenever, the an element or the viewport is scrolled, we will fire a
scroll event. The changes push a scroll event whenever an API causes a
scroll position to change.

Testing: New WPT tests for basic APIs.
Part of: https://github.com/servo/servo/issues/31665

---------

Signed-off-by: Jo Steven Novaryo <jo.steven.novaryo@huawei.com>

tests/wpt/meta/MANIFEST.json

@@ -467655,6 +467655,10 @@
        "5df4fa279363798f2f471467ed674c092c7a1749",
        []
       ],
+      "large-dimension-document.sub.html": [
+       "5d29f7be0bbb77e6303598aef833a810e84b6e80",
+       []
+      ],
       "prefixed-animation-event-tests.js": [
        "021b6bb9dfdc422d1a6c3c9c4a1a039f89a901d5",
        []
@@ -633745,6 +633749,20 @@
         }
        ]
       ],
+      "scroll-event-fired-to-element.html": [
+       "3484a2ec92b2bd8faa1d5147568f13a83b8c59d9",
+       [
+        null,
+        {}
+       ]
+      ],
+      "scroll-event-fired-to-iframe.html": [
+       "2ff3de79d33fa0a676a0eda4f109b6d0e634cc9d",
+       [
+        null,
+        {}
+       ]
+      ],
       "scrollend-event-fired-after-sequence-of-scrolls.tentative.html": [
        "dab6dcc9bd8d67a514ca95daf3e1d64b10a45188",
        [