Synthetic CDI beans should have a beanClass attribute of the CDI extension

The beanClass attribute of CDI beans is currently configured in a way that results in incorrectly identifying implementation class of synthetic beans. The beanClass attribute of beans is used by Weld (the reference/compatible impl) to determine how and where to define a proxy class. The problem was recently noticed in [WildFly](https://github.com/wildfly/wildfly/pull/16155), where synth beans from Soteria were registered under a different module. Synthetic beans should have a beanClass attribute of the CDI extension that registers them.

@manovotn

No files or tests are named. Start by locating the code that registers synthetic CDI beans and the CDI extension metadata it supplies, then trace how beanClass is assigned; done means synthetic beans identify the registering CDI extension and the relevant tests cover this behavior.

Written by the indexing model from the issue text.