[IMP] web: core: draggable: execute willStartDrag

Before this commit, the draggable hook did not execute willStartDrag, that is, before
the element is actually moved.

After this commit it does, allowing for implementing some features, like copyOnDrag.

Part-of: odoo/odoo#115799

addons/web/static/src/core/utils/draggable.js

@@ -43,6 +43,7 @@ import { pick } from "@web/core/utils/objects";
 /** @type {(params: DraggableParams) => DraggableState} */
 export const useDraggable = makeDraggableHook({
     name: "useDraggable",
+    onWillStartDrag: ({ctx}) => pick(ctx.current, "element"),
     onDragStart: ({ ctx }) => pick(ctx.current, "element"),
     onDrag: ({ ctx }) => pick(ctx.current, "element"),
     onDragEnd: ({ ctx }) => pick(ctx.current, "element"),