Implement unwrap() in Hibernate ORM StatelessSession proxies

So that Hibernate Data Repositories can work correctly.

Author: yrodiere

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/StatelessSessionLazyDelegator.java

@@ -502,4 +502,9 @@ public CacheMode getCacheMode() {
     public void setCacheMode(CacheMode cacheMode) {
         delegate.get().setCacheMode(cacheMode);
     }
+
+    @Override
+    public <T> T unwrap(Class<T> type) {
+        return delegate.get().unwrap(type);
+    }
 }

extensions/hibernate-orm/runtime/src/main/java/io/quarkus/hibernate/orm/runtime/session/TransactionScopedStatelessSession.java

@@ -875,4 +875,15 @@ public void setCacheMode(CacheMode cacheMode) {
             emr.statelessSession.setCacheMode(cacheMode);
         }
     }
+
+    @Override
+    public <T> T unwrap(Class<T> type) {
+        if (type.isAssignableFrom(StatelessSession.class)) {
+            return (T) this;
+        }
+        checkBlocking();
+        try (SessionResult emr = acquireSession()) {
+            return emr.statelessSession.unwrap(type);
+        }
+    }
 }