fix: can't properly drag and drop in empty record group (#9039)

Fix #8968 

Fix issue with drag and drop when record group are empty.
Happy to discuss the implementation, as it's limited to the
`@hello-pangea/dnd` api.

---------

Co-authored-by: Charles Bochet <charles@twenty.com>

packages/twenty-front/src/utils/combineRefs.ts

@@ -0,0 +1,15 @@
+import { isFunction } from '@sniptt/guards';
+import { MutableRefObject, Ref } from 'react';
+import { isDefined } from '~/utils/isDefined';
+
+export const combineRefs = <T>(...refs: (Ref<T> | undefined)[]) => {
+  return (node: T) => {
+    for (const ref of refs) {
+      if (isFunction(ref)) {
+        ref(node);
+      } else if (isDefined(ref) && 'current' in ref) {
+        (ref as MutableRefObject<T | null>).current = node;
+      }
+    }
+  };
+};