camel-core-model - Get rid of using JAXB

JAXB is a pain for the the legacy XML DSL (spring <beans> and blueprint XML).
Also JAXB is no longer in the JDK and its heavy to use.

We have the new fast XML IO parser that we use for modern Camel apps.

We should find a way in the future to get rid of JAXB in the core model and use a different way of generating the XML XSD.

The current generator with some legacy maven plugins that generate JAXB -> XML Schema is brittle and will be in the future with modern JVM versions.

Today we hit problems with this where generating OSGi XML does not work but it works for Spring XML.