Support generating multiple nodes from once in `registerNodeFactory`

[ftomassetti]

This is a continuation of #211

Currently we need to use work-arounds such:

 registerNodeFactory(TryStatement::class) {
        if (it.onExceptions.isEmpty()) {
            // Dummy try-catch, we will just take the body
            JBlockStmt(translateList(it.statements)).dummyBlock()
        } else {
            TODO()
        }
    }

Where:

/**
 * We cannot directly translate a statement into a sequence of statements, so we use these dummy blocks, which we
 * should later remove
 */
fun JBlockStmt.dummyBlock(): JBlockStmt {
    val annotationInstance = DynamicAnnotationInstance(UUID.randomUUID().toString(), JavaGenerationLanguage.dummyBlock)
    annotations.add(annotationInstance)
    return this
}

Some preparatory work has been done in #211 but it must be completed so that we can write something like:

 registerNodeFactory(TryStatement::class) {
        if (it.onExceptions.isEmpty()) {
           translateList(it.statements)
        } else {
            TODO()
        }
    }

[ftomassetti]

It seems that we have already this functionality. See registerMultipleNodeFactory.
@martin-azpillaga could you check if this is what you need?