feat: add safe xr hook

Author: itsdouges

packages/react/xr/src/xr.tsx

@@ -144,6 +144,14 @@ export function useXRStore() {
   return store
 }
 
+/**
+ * Hook for getting the xr store from context. If not available `undefined` is returned.
+ */
+export function useXRStoreSafe() {
+  const store = useContext(xrContext)
+  return store
+}
+
 /**
  * Hook for reading the state from the xr store
  */