fix(renderer): fix missing slot ref callback handling

fixes one of the issues raised in #5335

adds a new internal variable which is stored during vnode rendering to reuse it within the relocatedNodes logic

src/declarations/stencil-private.ts

@@ -1331,6 +1331,12 @@ export interface RenderNode extends HostElement {
    */
   host?: Element;
 
+  /**
+   * On Ref Function:
+   * Callback function to be called when the slotted node ref is ready.
+   */
+  ['s-rf']?: (elm: Element) => unknown;
+
   /**
    * Is initially hidden
    * Whether this node was originally rendered with the `hidden` attribute.

src/runtime/dom-extras.ts

@@ -47,6 +47,7 @@ export const patchCloneNode = (HostElementPrototype: HTMLElement) => {
         's-ol',
         's-nr',
         's-si',
+        's-rf',
       ];
 
       for (; i < srcNode.childNodes.length; i++) {

src/runtime/vdom/vdom-render.ts

@@ -149,6 +149,9 @@ const createElm = (oldParentVNode: d.VNode, newParentVNode: d.VNode, childIndex:
       // remember the slot name, or empty string for default slot
       elm['s-sn'] = newVNode.$name$ || '';
 
+      // remember the ref callback function
+      elm['s-rf'] = newVNode.$attrs$?.ref;
+
       // check if we've got an old vnode for this slot
       oldVNode = oldParentVNode && oldParentVNode.$children$ && oldParentVNode.$children$[childIndex];
       if (oldVNode && oldVNode.$tag$ === newVNode.$tag$ && oldParentVNode.$elm$) {
@@ -1094,6 +1097,8 @@ render() {
               }
             }
           }
+
+          nodeToRelocate && typeof slotRefNode['s-rf'] === 'function' && slotRefNode['s-rf'](nodeToRelocate);
         } else {
           // this node doesn't have a slot home to go to, so let's hide it
           if (nodeToRelocate.nodeType === NODE_TYPE.ElementNode) {