script: Pass more information to the MouseEvent constructor (#37672)

- Instead of eagerly computing `pageX` and `pageY`, collect the offset
  from the content's initial containing block in the compositor and pass
  that information through to `MouseEvent`. This prevents a layout flush
  that was happening when eagerly trying to fetch `Document` scroll
  offsets.
- Pass keyboard modifiers properly to `MouseEvent`.
- Now all this information is stored and passed as `Point2D` (typed) and
  `Modifiers` which greatly reduces the amount of arguments that need to
  be passed around.

Testing: It is difficult to test input events as they require WebDriver
which
isn't completely working yet. I have manually run Speedometer 2.1 and I
have
verified that this fixes the regression from #37601.
Fixes: #37601.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/script/dom/htmlinputelement.rs

@@ -2853,8 +2853,11 @@ impl VirtualMethods for HTMLInputElement {
                     // now.
                     if let Some(point_in_target) = mouse_event.point_in_target() {
                         let window = self.owner_window();
-                        let index =
-                            window.text_index_query(self.upcast::<Node>(), point_in_target, can_gc);
+                        let index = window.text_index_query(
+                            self.upcast::<Node>(),
+                            point_in_target.to_untyped(),
+                            can_gc,
+                        );
                         // Position the caret at the click position or at the end of the current
                         // value.
                         let edit_point_index = match index {