Minor JPA cleanups; part of overall refactoring effort (#6435)

Signed-off-by: Laird Nelson <laird.nelson@oracle.com>

integrations/cdi/jpa-cdi/src/main/java/io/helidon/integrations/cdi/jpa/AfterCompletionSynchronization.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.helidon.integrations.cdi.jpa;
+
+import java.util.Objects;
+import java.util.function.IntConsumer;
+
+import jakarta.transaction.Synchronization;
+
+final class AfterCompletionSynchronization implements IntConsumer, Synchronization {
+
+    private final IntConsumer afterCompletion;
+
+    AfterCompletionSynchronization(IntConsumer afterCompletion) {
+        super();
+        this.afterCompletion = Objects.requireNonNull(afterCompletion, "afterCompletion");
+    }
+
+    @Override
+    public void beforeCompletion() {
+
+    }
+
+    @Override
+    public void afterCompletion(int completedTransactionStatus) {
+        this.accept(completedTransactionStatus);
+    }
+
+    @Override
+    public void accept(int completedTransactionStatus) {
+        this.afterCompletion.accept(completedTransactionStatus);
+    }
+
+}