implements optimistic locking for PackageEntity

src/main/java/net/hostsharing/hsadminng/hs/hspackage/PackageEntity.java

@@ -19,6 +19,9 @@ public class PackageEntity {
 
     private @Id UUID uuid;
 
+    @Version
+    private int version;
+
     @ManyToOne(optional = false)
     @JoinColumn(name = "customeruuid")
     private CustomerEntity customer;

src/main/resources/db/changelog/2022-07-29-070-hs-package.sql

@@ -7,6 +7,7 @@
 create table if not exists package
 (
     uuid         uuid unique references RbacObject (uuid),
+    version      int not null default 0,
     customerUuid uuid references customer (uuid),
     name         varchar(5),
     description  varchar(96)