LPS-48577 Make the springs config locations extensible.

If you register new services than implements the SpringDescriptor interface, you can add new spring configurations to the tests spring context.
LPS-48577 Add the LiferayContextCreatedEvent

This event will be launched after the Spring and OSGI contexts of the tests have been created.
LPS-48577 Extension to launch PersistenceTest environment
LPS-48577 Compile the persistence-arquillian-extension
LPS-48577 Publish the module to the local maven repo when deploying, so that it could available as a dependency (and could be resolved by ivy or maven)