JSF: Fix and implement getBeansInScope in EL resolvers

[NicolaIsotta]

• Fix the null check bug in JsfELVariableResolver.getBeansInScope
• implement getBeansInScope in WebBeansELVariableResolver for CDI beans
• add unit tests for the entire JsfELVariableResolver class
• refactor WebBean to record
• add a TODO for a future fix

To a give a bit of reference: jsf implementations expose standard scope maps via EL references (eg. applicationScope, requestScope, etc) -> https://jakarta.ee/specifications/faces/4.0/jakarta-faces-4.0#a2830
This means that a bean can also be accessed via its scope: if we have a bean like this:

@Named
@ApplicationScoped
public class MyApplicationBean {
}

Usually accessible via #{myApplicationBean}, can be accessed also via #{applicationScope.myApplicationBean}. This PR fixes NB suggestion for the scope elements, both for CDI and old-school JSF beans.

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[mbien]

looks good