Switch to org.wrensecurity.wrenam groupId and cleanup POMs

[pavelhoral]

Performed changes:

• uniformly formatted all POMs (basic order of elements, indentation, newlines)
• switched groupId to org.wrensecurity.wrenam (this was the main goal)
• renamed parent artifactId from openam to wrenam-project
• switched to the latest wrensec-parent (changing versions of managed Maven plugins)
• switched to the latest wrensec-commons (changing versions of managed dependencies)
• switched to wrensec-guava (changing shaded package name)
• changed version to 15.0.0-SNAPSHOT to mark full Wren Security transition
• dropped unnecessary THIRD-PARTY.properties files that tracked licenses for dependencies
• dropped unnecessary Maven profiles (connected with former's vendor publishing pipeline and OEM packaging)
• fixed build number injection and switched to reproducible timestamp stored in top-level POM
• updated product name in configurator messages

Additional comments:

• I had to keep Mockito dependency at an older version because the latest one is not compatible with PowerMock. And even though I am not a big fan of PowerMock, it is here to stay - there are a lot of components that wouldn't be testable without it.
• I have removed almost all modules from dependencyManagement section of the parent POM and left only the most shared ones. This was done to make the parent POM simpler - if we want to have a proper BOM, we might want to create proper dedicated BOM module in the future.

[fyrbach]

LGTM