Initial transformation-based tech preview EE 9 variant of WildFly

Produce an initial EE 9 variant of WildFly as described in https://wildfly.org/news/2020/06/23/WildFly-and-Jakarta-EE-9/ and https://lists.jboss.org/archives/list/wildfly-dev@lists.jboss.org/thread/EMSDVYUE4YKXJJKGIJBI3QJORG3YZAL2/

This would be intended to be a milestone type release, not expected to pass the EE 9 TCK and likely not passing significant parts of the WildFly testsuite. The basic goal is to provide something to the community to look at and to surface technical issues.

Many dependencies used by this initial version may not be Final releases of the respective components.

Basic goals:

1) Produce an EE 9 variant of the wildfly-ee feature pack.
2) Galleon tooling to produce that feature pack and to provision a server from it that, at provisioning time, transforms any EE 8 (javax.* namespace) artifacts to EE 9 (jakarta.*).
3) Produce a fat server dist from that feature pack.
4) Server should be able to transform EE 8 managed deployments to EE 9 when the management layer accepts the deployment content.

Nice-to-have goals:

1) A variant of the full 'wildfly' feature pack (which brings various MP specs) that depends on the EE 9 wildfly-ee one.
2) Dist based on that.

Non-goals:

1) Thin server distributions.
2) Support for supplemental things like legacy Hibernate versions or JSF integrations beyond the default mojarra.
3) Domain mode support for legacy AS 7 extensions that were replaced in WildFly 8.
4) Support for the legacy security subsystem, picketlink extensions, or agroal.

Other technical points:

The default messaging configuration likely will not be for an embedded broker.