HHH-19871 Envers migration to JUnit 6

- Created new envers-junit hooks and hibernate-testing changes
- Migrated the `org.hibernate.orm.test.envers.integration` package

Author: mbellade

hibernate-envers/hibernate-envers.gradle

@@ -30,6 +30,8 @@ dependencies {
     testImplementation testLibs.junit4
     testImplementation testLibs.junit4Engine
 
+    testImplementation project(':hibernate-testing')
+
     testAnnotationProcessor project( ':hibernate-processor' )
 }