Add helper text to drag-and-drop elements to explain why an element is invalid

[katiestahl]

Feature description

Currently, we just show a red X if the element is invalid. We should explain to a user why the element is invalid so they can fix it

Use case

I am frustrated when trying to build a fusion and the UI tells me my component for the fusion is invalid, but I have no idea why

Proposed solution

Add messaging/helper text to guide a user to valid components

Alternatives considered

No response

Implementation details

No response

Potential Impact

No response

Additional context

No response

Contribution

Yes, I can create a PR for this feature.