When crafting a component, subcomponents are expected to be provided

one-by-one. This is fine in typical usage, but if a component needs to

pre-build subcomponent state and pass it in as an array of

subcomponents, then this will fail.
What happens is that the array of subcomponents ends up being provided

as a single child to a component. This doesn't get seen as subcomponent

information, since it's an array and not a subcomponent object.
Since the grammar doesn't provide something like ...${subcomponents}

outside of a <tag>, we instead need to handle this in the crafting

implementation.
We now handle any children that are arrays as possible lists of

subcomponents. We'll never have an array as a valid child outside of

this, so this should be safe and shouldn't impact any other usage.
This problem was first encountered in MenuButton.

All unit tests pass.
Hit this with MenuButton and verified I could capture and pass along

arrays of subcomponents.