Problem/Motivation
SDCs should be able to limit what components are allowed within its respective slots.
An example use case of this is that an accordion_group component should only allow an accordion_item component in it's main slot.
Similar use cases are tab groups and tab items, or a card carousel and a card.
We also need to ensure this works if the replaces key is being used where a theme replaces a module's component with its own.
Note that this is a vital use case for Experience Builder which is due Q3 this year.