Replace Axis with Apache CXF

[natechadwick]

Describe the bug
The legacy SOAP services are currently using an end-of-life version of Apache Axis. We already use Apache CXF for JAX-RS and Rest API services. We should migrate the SOAP API to JAX-WS and bump the API version to 8.0.0

Key Points

1. Minimize API model / interface changes to as few as possible
2. Use CXF code generator to generate the API
3. Change the package name to API for the generated web services code for Java 9 module support, currently it overlaps with a package in system.
4. Update the Loader smaple application for new version
5. Create a new version of the Web Service Development doc for the new version of the API
6. Update the Tools projects and Content Explorer to use the new API.
7. Create a separate webservices-client modules that will contain the new Client stubs / JAX-WS client.