Fix for WFGP-284, Embedded server execution should be isolated in its own classloader

[jfdenise]

Isolated execution of Embedded Server during provisioning.

• Config generation is operated from 2 classloaders. First one load the config generator + CLI (DMR, ...). This one delegates to the context classloader. That is OK, no embedded server part.
• The second one only load the embedded server + all its dependencies (such as DMR all from cli:client) + JBoss Modules

So DMR is loaded twice. In the first classloader, converted to yaml String to be consumed on the embedded side.

This isolation should be even more strict than the forked process approach.

[jamezp]

In general this looks okay. I'm not sure I feel about the odd cases for variables, but that's just a personal preference :) I also understand it makes it look more like real calls so I do get that part.

I do wonder a bit if we should be using MethodHandle's instead of reflection. Likely not a huge deal, but there may be some performance impact. It might not be enough to worry about though.