Issue #3587024: Handle decrease of cardinality

Closes #3587024

Update the component instance when reducing the cardinality.

Testing steps

• Create a code component with a multivalue prop (no limit or higher limit).
• Add content with 4 or more values to a page using that component.
• Confirm that the "+ Add new" button is available.
• Update the component definition to set a maximum of 3 values on that prop and "Add to components".
• Load any page containing the affected component instance. Confirm the component fails gracefully (page renders, component does not).
• Open the component tree for editing. Confirm the component instance was auto-updated: only 3 values remain, excess was truncated.
• Confirm the "+ Add new" button is not available.
• Save and reload the page. Confirm the component renders without error.
• Edit again the component and convert it to unlimited.
• Load the page and confirm that the "+ Add new" button is available again.