Fixed tooltip (#74074)

Co-authored-by: Elastic Machine <[email protected]>

Author: VladLasitsa

src/plugins/vis_type_vega/public/_vega_vis.scss

@@ -107,6 +107,7 @@
 
 .vgaVis__tooltip {
   max-width: 100%;
+  position: fixed;
 
   h2 {
     margin-bottom: $euiSizeS;

src/plugins/vis_type_vega/public/vega_view/vega_tooltip.js

@@ -85,12 +85,12 @@ export class TooltipHandler {
     let anchorBounds;
     if (item.bounds.width() > this.centerOnMark || item.bounds.height() > this.centerOnMark) {
       // I would expect clientX/Y, but that shows incorrectly
-      anchorBounds = createRect(event.pageX, event.pageY, 0, 0);
+      anchorBounds = createRect(event.clientX, event.clientY, 0, 0);
     } else {
       const containerBox = this.container.getBoundingClientRect();
       anchorBounds = createRect(
-        containerBox.left + view._origin[0] + item.bounds.x1 + window.pageXOffset,
-        containerBox.top + view._origin[1] + item.bounds.y1 + window.pageYOffset,
+        containerBox.left + view._origin[0] + item.bounds.x1,
+        containerBox.top + view._origin[1] + item.bounds.y1,
         item.bounds.width(),
         item.bounds.height()
       );