Verify that A2UI content using the basic catalog that refers to functions can render correctly

[jacobsimionato]

We have found that functions are not implemented for inference purposes in the Gen UI SDK - see #873

We should check whether A2UI content from a different source (e.g. server) that uses functions can render correctly. I think we should fix rendering before we fix inference, because there is less ambiguity. I suspect it does work, but we should confirm it does, perhaps by using the "composer" app and adding a layout that uses functions.