HHH-19348 Change scope of private methods in IdentifierLoadAccessImpl

For Hibernate Reactive

Change scopes of some private methods, and small refactoring to avoid
duplication in Hibernate Reactive.

Related to hibernate/hibernate-reactive#2181

Author: DavideD

hibernate-core/src/main/java/org/hibernate/loader/internal/IdentifierLoadAccessImpl.java

@@ -129,7 +129,8 @@ protected T doGetReference(Object id) {
 				concreteType.getEntityName(), lockOptions, isReadOnly( session ) );
 	}
 
-	private Boolean isReadOnly(SessionImplementor session) {
+	// Hibernate Reactive might need to call this
+	protected Boolean isReadOnly(SessionImplementor session) {
 		return readOnly != null
 				? readOnly
 				: session.getLoadQueryInfluencers().getReadOnly();